diff --git a/benchmark/Makefile b/benchmark/Makefile
index a05a8cb..a33b9d4 100644
--- a/benchmark/Makefile
+++ b/benchmark/Makefile
@@ -1,4 +1,7 @@
 
+SRC = ./
+CPP  = $(shell find $(SRC) -name '*.cpp')
+
 CFLAGS = -std=c++11 -lstdc++ -Wall -I../src/ -L../
 
 all: parser_benchmark
@@ -6,8 +9,8 @@ all: parser_benchmark
 run: parser_benchmark
 	@export LD_LIBRARY_PATH=${LD_LIBRARY_PATH}:../ && ./parser_benchmark
 
-parser_benchmark: parser_benchmark.cpp
-	$(CXX) $(CFLAGS) parser_benchmark.cpp -o parser_benchmark -lbenchmark -lpthread -lsqlparser
+parser_benchmark: $(CPP)
+	$(CXX) $(CFLAGS) $(CPP) -o parser_benchmark -lbenchmark -lpthread -lsqlparser
 
 clean:
 	rm -f parser_benchmark
diff --git a/benchmark/parser_benchmark.cpp b/benchmark/parser_benchmark.cpp
index 9f0fa07..cea4709 100644
--- a/benchmark/parser_benchmark.cpp
+++ b/benchmark/parser_benchmark.cpp
@@ -31,6 +31,18 @@ PARSE_QUERY_BENCHMARK(BM_LongSelectElement26,
 PARSE_QUERY_BENCHMARK(BM_LongSelectElement52,
   "SELECT aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa FROM test;");
 
+// Prepare and Execute benchmarks.
+PARSE_QUERY_BENCHMARK(BM_ExecuteStatement,
+  "EXECUTE procedure;");
+
+PARSE_QUERY_BENCHMARK(BM_ExecuteWith2ParametersStatement,
+  "EXECUTE procedure(11, 'test');");
+
+PARSE_QUERY_BENCHMARK(BM_ExecuteWith10ParametersStatement,
+  "EXECUTE procedure(11, 'test', 5.6, 4.2, 'abc', 6, 7, 8, 9, 10000);");
+
+
+
 // Benchmark the influence of increasing size of the query, while
 // the number of tokens remains unchanged.
 static void BM_CharacterCount(benchmark::State& st) {
diff --git a/example/example.cpp b/example/example.cpp
index 2b67c90..9961d3d 100644
--- a/example/example.cpp
+++ b/example/example.cpp
@@ -6,7 +6,7 @@
 #include "SQLParser.h"
 
 // contains printing utilities
-#include "sqlhelper.h"
+#include "util/sqlhelper.h"
 
 int main(int argc, char *argv[]) {
     if (argc <= 1) {
@@ -16,31 +16,26 @@ int main(int argc, char *argv[]) {
     std::string query = argv[1];
 
     // parse a given query
-    hsql::SQLParserResult* result = hsql::SQLParser::parseSQLString(query);
+    hsql::SQLParserResult result;
+    hsql::SQLParser::parseSQLString(query, &result);
 
     // check whether the parsing was successful
-    if (!result) {
-        return -1;
-    }
 
-    if (result->isValid()) {
+    if (result.isValid()) {
         printf("Parsed successfully!\n");
-        printf("Number of statements: %lu\n", result->size());
+        printf("Number of statements: %lu\n", result.size());
 
-        for (uint i = 0; i < result->size(); ++i) {
+        for (uint i = 0; i < result.size(); ++i) {
             // Print a statement summary.
-            hsql::printStatementInfo(result->getStatement(i));
+            hsql::printStatementInfo(result.getStatement(i));
         }
-
-        delete result;
         return 0;
     } else {
         fprintf(stderr, "Given string is not a valid SQL query.\n");
         fprintf(stderr, "%s (L%d:%d)\n", 
-                result->errorMsg(),
-                result->errorLine(),
-                result->errorColumn());
-        delete result;
+                result.errorMsg(),
+                result.errorLine(),
+                result.errorColumn());
         return -1;
     }
 }
diff --git a/src/SQLParser.cpp b/src/SQLParser.cpp
index 55ae5f7..a33f84d 100644
--- a/src/SQLParser.cpp
+++ b/src/SQLParser.cpp
@@ -12,36 +12,51 @@ namespace hsql {
     fprintf(stderr, "SQLParser only has static methods atm! Do not initialize!\n");
   }
 
-  SQLParserResult* SQLParser::parseSQLString(const char* text) {
-    SQLParserResult* result = NULL;
+  // static
+  bool SQLParser::parseSQLString(const char* text, SQLParserResult* result) {
     yyscan_t scanner;
     YY_BUFFER_STATE state;
 
     if (hsql_lex_init(&scanner)) {
       // Couldn't initialize the lexer.
       fprintf(stderr, "[Error] SQLParser: Error when initializing lexer!\n");
-      return NULL;
+      return false;
     }
 
     state = hsql__scan_string(text, scanner);
 
-    // Parser and return early if it failed.
-    if (hsql_parse(&result, scanner)) {
-      // Returns an error stmt object.
-      hsql__delete_buffer(state, scanner);
-      hsql_lex_destroy(scanner);
-      return result;
-    }
+    // Parse the tokens.
+    // If parsing fails, the result will contain an error object.
+    int ret = hsql_parse(result, scanner);
+    bool success = (ret == 0);
+    result->setIsValid(success);
 
     hsql__delete_buffer(state, scanner);
     hsql_lex_destroy(scanner);
+
+    return true;
+  }
+
+  // static
+  bool SQLParser::parseSQLString(const std::string& text, SQLParserResult* result) {
+    return parseSQLString(text.c_str(), result);
+  }
+
+  // static
+  SQLParserResult* SQLParser::parseSQLString(const char* text) {
+    SQLParserResult* result = new SQLParserResult();
+
+    if (!SQLParser::parseSQLString(text, result)) {
+      delete result;
+      return NULL;
+    }
+
     return result;
   }
 
-
+  // static
   SQLParserResult* SQLParser::parseSQLString(const std::string& text) {
     return parseSQLString(text.c_str());
   }
 
-
-} // namespace hsql
\ No newline at end of file
+} // namespace hsql
diff --git a/src/SQLParser.h b/src/SQLParser.h
index 5bb2a4a..e494680 100644
--- a/src/SQLParser.h
+++ b/src/SQLParser.h
@@ -1,5 +1,5 @@
-#ifndef __SQLPARSER_H_
-#define __SQLPARSER_H_
+#ifndef __SQLPARSER__SQLPARSER_H__
+#define __SQLPARSER__SQLPARSER_H__
 
 #include "SQLParserResult.h"
 #include "sql/statements.h"
@@ -9,10 +9,25 @@ namespace hsql {
   // Static methods used to parse SQL strings.
   class SQLParser {
    public:
+    // Parses a given constant character SQL string into the result object.
+    // Returns true if the lexer and parser could run without internal errors.
+    // This does NOT mean that the SQL string was valid SQL. To check that
+    // you need to check result->isValid();
+    static bool parseSQLString(const char* sql, SQLParserResult* result);
+
+    // Parses a given SQL string into the result object.
+    static bool parseSQLString(const std::string& sql, SQLParserResult* result);
+
+    // Deprecated:
     // Parses a given constant character SQL string.
+    // Note: This is kept for legacy reasons. It is recommended to use
+    //       the (const char*, SQLParserResult*) implementation.
     static SQLParserResult* parseSQLString(const char* sql);
 
+    // Deprecated:
     // Parses an SQL std::string.
+    // Note: This is kept for legacy reasons. It is recommended to use
+    //       the (const std::string&, SQLParserResult*) implementation.
     static SQLParserResult* parseSQLString(const std::string& sql);
 
    private:
diff --git a/src/SQLParserResult.cpp b/src/SQLParserResult.cpp
index ca106c9..b8df999 100644
--- a/src/SQLParserResult.cpp
+++ b/src/SQLParserResult.cpp
@@ -4,21 +4,17 @@
 namespace hsql {
 
   SQLParserResult::SQLParserResult() :
-    isValid_(true),
+    isValid_(false),
     errorMsg_(NULL) {};
 
   SQLParserResult::SQLParserResult(SQLStatement* stmt) :
-    isValid_(true),
+    isValid_(false),
     errorMsg_(NULL) {
     addStatement(stmt);
   };
 
   SQLParserResult::~SQLParserResult() {
-    for (SQLStatement* statement : statements_) {
-      delete statement;
-    }
-
-    free(errorMsg_);
+    reset();
   }
 
   void SQLParserResult::addStatement(SQLStatement* stmt) {
@@ -63,4 +59,30 @@ namespace hsql {
     errorColumn_ = errorColumn;
   }
 
-} // namespace hsql
\ No newline at end of file
+  const std::vector<SQLStatement*>& SQLParserResult::getStatements() const {
+    return statements_;
+  }
+
+  std::vector<SQLStatement*> SQLParserResult::releaseStatements() {
+    std::vector<SQLStatement*> copy = statements_;
+
+    statements_.clear();
+
+    return copy;
+  }
+
+  void SQLParserResult::reset() {
+    for (SQLStatement* statement : statements_) {
+      delete statement;
+    }
+    statements_.clear();
+
+    isValid_ = false;
+
+    free(errorMsg_);
+    errorMsg_ = NULL;
+    errorLine_ = -1;
+    errorColumn_ = -1;
+  }
+
+} // namespace hsql
diff --git a/src/SQLParserResult.h b/src/SQLParserResult.h
index 96e19cf..570664c 100644
--- a/src/SQLParserResult.h
+++ b/src/SQLParserResult.h
@@ -1,5 +1,5 @@
-#ifndef __SQLPARSERRESULT__
-#define __SQLPARSERRESULT__
+#ifndef __SQLPARSER__SQLPARSER_RESULT_H__
+#define __SQLPARSER__SQLPARSER_RESULT_H__
 
 #include "sql/SQLStatement.h"
 
@@ -15,15 +15,22 @@ namespace hsql {
     // Takes ownership of the statement.
     SQLParserResult(SQLStatement* stmt);
 
-    // Deletes all statements in the resul.
+    // Deletes all statements in the result.
     virtual ~SQLParserResult();
 
+    // Set whether parsing was successful.
+    void setIsValid(bool isValid);
+
     // Returns true if parsing was successful.
     bool isValid() const;
 
     // Returns the number of statements in the result.
     size_t size() const;
 
+    // Set the details of the error, if available.
+    // Takes ownership of errorMsg.
+    void setErrorDetails(char* errorMsg, int errorLine, int errorColumn);
+
     // Returns the error message, if an error occurred.
     const char* errorMsg() const;
 
@@ -33,23 +40,25 @@ namespace hsql {
     // Returns the column number of the occurrance of the error in the query.
     int errorColumn() const;
 
+    // Adds a statement to the result list of statements.
+    // SQLParserResult takes ownership of the statement.
+    void addStatement(SQLStatement* stmt);
+
     // Gets the SQL statement with the given index.
     const SQLStatement* getStatement(int index) const;
 
     // Gets the non const SQL statement with the given index.
     SQLStatement* getMutableStatement(int index);
 
-    // Adds a statement to the result list of statements.
-    // Takes ownership of the statement.
-    void addStatement(SQLStatement* stmt);
+    // Get the list of all statements.
+    const std::vector<SQLStatement*>& getStatements() const;
 
-    // Set whether parsing was successful.
-    void setIsValid(bool isValid);
-
-    // Set the details of the error, if available.
-    // Takes ownership of errorMsg.
-    void setErrorDetails(char* errorMsg, int errorLine, int errorColumn);
+    // Returns a copy of the list of all statements in this result.
+    // Removes them from this result.
+    std::vector<SQLStatement*> releaseStatements();
 
+    // Deletes all statements and other data within the result.
+    void reset();
 
    private:
     // List of statements within the result.
@@ -70,4 +79,4 @@ namespace hsql {
 
 } // namespace hsql
 
-#endif // __SQLPARSERRESULT__
\ No newline at end of file
+#endif // __SQLPARSER__SQLPARSER_RESULT_H__
\ No newline at end of file
diff --git a/src/parser/bison_parser.cpp b/src/parser/bison_parser.cpp
index 6db91ac..4c71941 100644
--- a/src/parser/bison_parser.cpp
+++ b/src/parser/bison_parser.cpp
@@ -91,21 +91,16 @@
 
 using namespace hsql;
 
-int yyerror(YYLTYPE* llocp, SQLParserResult** result, yyscan_t scanner, const char *msg) {
-	delete *result;
-
-	SQLParserResult* list = new SQLParserResult();
-	list->setIsValid(false);
-	list->setErrorDetails(strdup(msg), llocp->first_line, llocp->first_column);
-
-	*result = list;
+int yyerror(YYLTYPE* llocp, SQLParserResult* result, yyscan_t scanner, const char *msg) {
+	result->setIsValid(false);
+	result->setErrorDetails(strdup(msg), llocp->first_line, llocp->first_column);
 	return 0;
 }
 
 
 
 
-#line 109 "bison_parser.cpp" /* yacc.c:339  */
+#line 104 "bison_parser.cpp" /* yacc.c:339  */
 
 # ifndef YY_NULLPTR
 #  if defined __cplusplus && 201103L <= __cplusplus
@@ -143,7 +138,7 @@ int yyerror(YYLTYPE* llocp, SQLParserResult** result, yyscan_t scanner, const ch
 extern int hsql_debug;
 #endif
 /* "%code requires" blocks.  */
-#line 41 "bison_parser.y" /* yacc.c:355  */
+#line 36 "bison_parser.y" /* yacc.c:355  */
 
 // %code requires block	
 
@@ -166,7 +161,7 @@ extern int hsql_debug;
         } \
     }
 
-#line 170 "bison_parser.cpp" /* yacc.c:355  */
+#line 165 "bison_parser.cpp" /* yacc.c:355  */
 
 /* Token type.  */
 #ifndef HSQL_TOKENTYPE
@@ -309,7 +304,7 @@ extern int hsql_debug;
 
 union HSQL_STYPE
 {
-#line 100 "bison_parser.y" /* yacc.c:355  */
+#line 95 "bison_parser.y" /* yacc.c:355  */
 
 	double fval;
 	int64_t ival;
@@ -337,7 +332,7 @@ union HSQL_STYPE
 	hsql::GroupByDescription* group_t;
 	hsql::UpdateClause* update_t;
 
-	hsql::SQLParserResult* stmt_list;
+	std::vector<hsql::SQLStatement*>* stmt_vec;
 
 	std::vector<char*>* str_vec;
 	std::vector<hsql::TableRef*>* table_vec;
@@ -346,7 +341,7 @@ union HSQL_STYPE
 	std::vector<hsql::Expr*>* expr_vec;
 	std::vector<hsql::OrderDescription*>* order_vec;
 
-#line 350 "bison_parser.cpp" /* yacc.c:355  */
+#line 345 "bison_parser.cpp" /* yacc.c:355  */
 };
 
 typedef union HSQL_STYPE HSQL_STYPE;
@@ -370,13 +365,13 @@ struct HSQL_LTYPE
 
 
 
-int hsql_parse (hsql::SQLParserResult** result, yyscan_t scanner);
+int hsql_parse (hsql::SQLParserResult* result, yyscan_t scanner);
 
 #endif /* !YY_HSQL_BISON_PARSER_H_INCLUDED  */
 
 /* Copy the second part of user declarations.  */
 
-#line 380 "bison_parser.cpp" /* yacc.c:358  */
+#line 375 "bison_parser.cpp" /* yacc.c:358  */
 
 #ifdef short
 # undef short
@@ -688,24 +683,24 @@ static const yytype_uint8 yytranslate[] =
   /* YYRLINE[YYN] -- Source line where rule number YYN was defined.  */
 static const yytype_uint16 yyrline[] =
 {
-       0,   245,   245,   252,   253,   257,   262,   267,   268,   269,
-     270,   271,   272,   273,   274,   275,   283,   288,   296,   300,
-     312,   320,   324,   334,   340,   346,   356,   357,   361,   362,
-     366,   373,   374,   375,   376,   386,   390,   394,   406,   414,
-     426,   432,   442,   443,   453,   462,   463,   467,   479,   480,
-     484,   485,   489,   499,   513,   527,   528,   529,   533,   545,
-     546,   550,   554,   559,   560,   564,   569,   573,   574,   577,
-     578,   582,   583,   587,   591,   592,   593,   599,   600,   604,
-     605,   606,   613,   614,   618,   619,   623,   630,   631,   632,
-     633,   634,   635,   639,   640,   641,   642,   643,   644,   648,
-     649,   650,   654,   655,   659,   660,   661,   662,   663,   664,
-     665,   666,   667,   671,   672,   676,   677,   678,   679,   684,
-     688,   689,   693,   694,   695,   696,   697,   698,   702,   706,
-     710,   711,   715,   716,   717,   721,   726,   727,   731,   735,
-     739,   750,   751,   761,   762,   768,   773,   774,   779,   789,
-     797,   798,   803,   804,   808,   809,   817,   829,   830,   831,
-     832,   833,   834,   835,   836,   837,   843,   849,   853,   862,
-     863,   868,   869
+       0,   240,   240,   251,   252,   256,   261,   266,   267,   268,
+     269,   270,   271,   272,   273,   274,   282,   287,   299,   303,
+     315,   323,   327,   337,   343,   349,   359,   360,   364,   365,
+     369,   376,   377,   378,   379,   389,   393,   397,   409,   417,
+     429,   435,   445,   446,   456,   465,   466,   470,   482,   483,
+     487,   488,   492,   502,   516,   530,   531,   532,   536,   548,
+     549,   553,   557,   562,   563,   567,   572,   576,   577,   580,
+     581,   585,   586,   590,   594,   595,   596,   602,   603,   607,
+     608,   609,   616,   617,   621,   622,   626,   633,   634,   635,
+     636,   637,   638,   642,   643,   644,   645,   646,   647,   651,
+     652,   653,   657,   658,   662,   663,   664,   665,   666,   667,
+     668,   669,   670,   674,   675,   679,   680,   681,   682,   687,
+     691,   692,   696,   697,   698,   699,   700,   701,   705,   709,
+     713,   714,   718,   719,   720,   724,   729,   730,   734,   738,
+     742,   753,   754,   764,   765,   771,   776,   777,   782,   792,
+     800,   801,   806,   807,   811,   812,   820,   832,   833,   834,
+     835,   836,   837,   838,   839,   840,   846,   852,   856,   865,
+     866,   871,   872
 };
 #endif
 
@@ -1221,7 +1216,7 @@ do {                                                                      \
 `----------------------------------------*/
 
 static void
-yy_symbol_value_print (FILE *yyoutput, int yytype, YYSTYPE const * const yyvaluep, YYLTYPE const * const yylocationp, hsql::SQLParserResult** result, yyscan_t scanner)
+yy_symbol_value_print (FILE *yyoutput, int yytype, YYSTYPE const * const yyvaluep, YYLTYPE const * const yylocationp, hsql::SQLParserResult* result, yyscan_t scanner)
 {
   FILE *yyo = yyoutput;
   YYUSE (yyo);
@@ -1243,7 +1238,7 @@ yy_symbol_value_print (FILE *yyoutput, int yytype, YYSTYPE const * const yyvalue
 `--------------------------------*/
 
 static void
-yy_symbol_print (FILE *yyoutput, int yytype, YYSTYPE const * const yyvaluep, YYLTYPE const * const yylocationp, hsql::SQLParserResult** result, yyscan_t scanner)
+yy_symbol_print (FILE *yyoutput, int yytype, YYSTYPE const * const yyvaluep, YYLTYPE const * const yylocationp, hsql::SQLParserResult* result, yyscan_t scanner)
 {
   YYFPRINTF (yyoutput, "%s %s (",
              yytype < YYNTOKENS ? "token" : "nterm", yytname[yytype]);
@@ -1283,7 +1278,7 @@ do {                                                            \
 `------------------------------------------------*/
 
 static void
-yy_reduce_print (yytype_int16 *yyssp, YYSTYPE *yyvsp, YYLTYPE *yylsp, int yyrule, hsql::SQLParserResult** result, yyscan_t scanner)
+yy_reduce_print (yytype_int16 *yyssp, YYSTYPE *yyvsp, YYLTYPE *yylsp, int yyrule, hsql::SQLParserResult* result, yyscan_t scanner)
 {
   unsigned long int yylno = yyrline[yyrule];
   int yynrhs = yyr2[yyrule];
@@ -1563,7 +1558,7 @@ yysyntax_error (YYSIZE_T *yymsg_alloc, char **yymsg,
 `-----------------------------------------------*/
 
 static void
-yydestruct (const char *yymsg, int yytype, YYSTYPE *yyvaluep, YYLTYPE *yylocationp, hsql::SQLParserResult** result, yyscan_t scanner)
+yydestruct (const char *yymsg, int yytype, YYSTYPE *yyvaluep, YYLTYPE *yylocationp, hsql::SQLParserResult* result, yyscan_t scanner)
 {
   YYUSE (yyvaluep);
   YYUSE (yylocationp);
@@ -1577,109 +1572,116 @@ yydestruct (const char *yymsg, int yytype, YYSTYPE *yyvaluep, YYLTYPE *yylocatio
   switch (yytype)
     {
           case 3: /* IDENTIFIER  */
-#line 142 "bison_parser.y" /* yacc.c:1257  */
+#line 137 "bison_parser.y" /* yacc.c:1257  */
       { free( (((*yyvaluep).sval)) ); }
-#line 1583 "bison_parser.cpp" /* yacc.c:1257  */
+#line 1578 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 4: /* STRING  */
-#line 142 "bison_parser.y" /* yacc.c:1257  */
+#line 137 "bison_parser.y" /* yacc.c:1257  */
       { free( (((*yyvaluep).sval)) ); }
-#line 1589 "bison_parser.cpp" /* yacc.c:1257  */
+#line 1584 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 5: /* FLOATVAL  */
-#line 141 "bison_parser.y" /* yacc.c:1257  */
+#line 136 "bison_parser.y" /* yacc.c:1257  */
       { }
-#line 1595 "bison_parser.cpp" /* yacc.c:1257  */
+#line 1590 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 6: /* INTVAL  */
-#line 141 "bison_parser.y" /* yacc.c:1257  */
+#line 136 "bison_parser.y" /* yacc.c:1257  */
       { }
-#line 1601 "bison_parser.cpp" /* yacc.c:1257  */
+#line 1596 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 7: /* NOTEQUALS  */
-#line 141 "bison_parser.y" /* yacc.c:1257  */
+#line 136 "bison_parser.y" /* yacc.c:1257  */
       { }
-#line 1607 "bison_parser.cpp" /* yacc.c:1257  */
+#line 1602 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 8: /* LESSEQ  */
-#line 141 "bison_parser.y" /* yacc.c:1257  */
+#line 136 "bison_parser.y" /* yacc.c:1257  */
       { }
-#line 1613 "bison_parser.cpp" /* yacc.c:1257  */
+#line 1608 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 9: /* GREATEREQ  */
-#line 141 "bison_parser.y" /* yacc.c:1257  */
+#line 136 "bison_parser.y" /* yacc.c:1257  */
       { }
-#line 1619 "bison_parser.cpp" /* yacc.c:1257  */
+#line 1614 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 153: /* statement_list  */
-#line 151 "bison_parser.y" /* yacc.c:1257  */
-      { delete (((*yyvaluep).stmt_list)); }
-#line 1625 "bison_parser.cpp" /* yacc.c:1257  */
+#line 138 "bison_parser.y" /* yacc.c:1257  */
+      {
+	if ((((*yyvaluep).stmt_vec)) != NULL) {
+		for (auto ptr : *(((*yyvaluep).stmt_vec))) {
+			delete ptr;
+		}
+	}
+	delete (((*yyvaluep).stmt_vec));
+}
+#line 1627 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 154: /* statement  */
-#line 151 "bison_parser.y" /* yacc.c:1257  */
+#line 146 "bison_parser.y" /* yacc.c:1257  */
       { delete (((*yyvaluep).statement)); }
-#line 1631 "bison_parser.cpp" /* yacc.c:1257  */
+#line 1633 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 155: /* preparable_statement  */
-#line 151 "bison_parser.y" /* yacc.c:1257  */
+#line 146 "bison_parser.y" /* yacc.c:1257  */
       { delete (((*yyvaluep).statement)); }
-#line 1637 "bison_parser.cpp" /* yacc.c:1257  */
+#line 1639 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 156: /* prepare_statement  */
-#line 151 "bison_parser.y" /* yacc.c:1257  */
+#line 146 "bison_parser.y" /* yacc.c:1257  */
       { delete (((*yyvaluep).prep_stmt)); }
-#line 1643 "bison_parser.cpp" /* yacc.c:1257  */
+#line 1645 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 157: /* execute_statement  */
-#line 151 "bison_parser.y" /* yacc.c:1257  */
+#line 146 "bison_parser.y" /* yacc.c:1257  */
       { delete (((*yyvaluep).exec_stmt)); }
-#line 1649 "bison_parser.cpp" /* yacc.c:1257  */
+#line 1651 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 158: /* import_statement  */
-#line 151 "bison_parser.y" /* yacc.c:1257  */
+#line 146 "bison_parser.y" /* yacc.c:1257  */
       { delete (((*yyvaluep).import_stmt)); }
-#line 1655 "bison_parser.cpp" /* yacc.c:1257  */
+#line 1657 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 159: /* import_file_type  */
-#line 141 "bison_parser.y" /* yacc.c:1257  */
+#line 136 "bison_parser.y" /* yacc.c:1257  */
       { }
-#line 1661 "bison_parser.cpp" /* yacc.c:1257  */
+#line 1663 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 160: /* file_path  */
-#line 142 "bison_parser.y" /* yacc.c:1257  */
+#line 137 "bison_parser.y" /* yacc.c:1257  */
       { free( (((*yyvaluep).sval)) ); }
-#line 1667 "bison_parser.cpp" /* yacc.c:1257  */
+#line 1669 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 161: /* create_statement  */
-#line 151 "bison_parser.y" /* yacc.c:1257  */
+#line 146 "bison_parser.y" /* yacc.c:1257  */
       { delete (((*yyvaluep).create_stmt)); }
-#line 1673 "bison_parser.cpp" /* yacc.c:1257  */
+#line 1675 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 162: /* opt_not_exists  */
-#line 141 "bison_parser.y" /* yacc.c:1257  */
+#line 136 "bison_parser.y" /* yacc.c:1257  */
       { }
-#line 1679 "bison_parser.cpp" /* yacc.c:1257  */
+#line 1681 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 163: /* column_def_commalist  */
-#line 143 "bison_parser.y" /* yacc.c:1257  */
+#line 138 "bison_parser.y" /* yacc.c:1257  */
       {
 	if ((((*yyvaluep).column_vec)) != NULL) {
 		for (auto ptr : *(((*yyvaluep).column_vec))) {
@@ -1688,47 +1690,47 @@ yydestruct (const char *yymsg, int yytype, YYSTYPE *yyvaluep, YYLTYPE *yylocatio
 	}
 	delete (((*yyvaluep).column_vec));
 }
-#line 1692 "bison_parser.cpp" /* yacc.c:1257  */
+#line 1694 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 164: /* column_def  */
-#line 151 "bison_parser.y" /* yacc.c:1257  */
+#line 146 "bison_parser.y" /* yacc.c:1257  */
       { delete (((*yyvaluep).column_t)); }
-#line 1698 "bison_parser.cpp" /* yacc.c:1257  */
+#line 1700 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 165: /* column_type  */
-#line 141 "bison_parser.y" /* yacc.c:1257  */
+#line 136 "bison_parser.y" /* yacc.c:1257  */
       { }
-#line 1704 "bison_parser.cpp" /* yacc.c:1257  */
+#line 1706 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 166: /* drop_statement  */
-#line 151 "bison_parser.y" /* yacc.c:1257  */
+#line 146 "bison_parser.y" /* yacc.c:1257  */
       { delete (((*yyvaluep).drop_stmt)); }
-#line 1710 "bison_parser.cpp" /* yacc.c:1257  */
+#line 1712 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 167: /* delete_statement  */
-#line 151 "bison_parser.y" /* yacc.c:1257  */
+#line 146 "bison_parser.y" /* yacc.c:1257  */
       { delete (((*yyvaluep).delete_stmt)); }
-#line 1716 "bison_parser.cpp" /* yacc.c:1257  */
+#line 1718 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 168: /* truncate_statement  */
-#line 151 "bison_parser.y" /* yacc.c:1257  */
+#line 146 "bison_parser.y" /* yacc.c:1257  */
       { delete (((*yyvaluep).delete_stmt)); }
-#line 1722 "bison_parser.cpp" /* yacc.c:1257  */
+#line 1724 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 169: /* insert_statement  */
-#line 151 "bison_parser.y" /* yacc.c:1257  */
+#line 146 "bison_parser.y" /* yacc.c:1257  */
       { delete (((*yyvaluep).insert_stmt)); }
-#line 1728 "bison_parser.cpp" /* yacc.c:1257  */
+#line 1730 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 170: /* opt_column_list  */
-#line 143 "bison_parser.y" /* yacc.c:1257  */
+#line 138 "bison_parser.y" /* yacc.c:1257  */
       {
 	if ((((*yyvaluep).str_vec)) != NULL) {
 		for (auto ptr : *(((*yyvaluep).str_vec))) {
@@ -1737,17 +1739,17 @@ yydestruct (const char *yymsg, int yytype, YYSTYPE *yyvaluep, YYLTYPE *yylocatio
 	}
 	delete (((*yyvaluep).str_vec));
 }
-#line 1741 "bison_parser.cpp" /* yacc.c:1257  */
+#line 1743 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 171: /* update_statement  */
-#line 151 "bison_parser.y" /* yacc.c:1257  */
+#line 146 "bison_parser.y" /* yacc.c:1257  */
       { delete (((*yyvaluep).update_stmt)); }
-#line 1747 "bison_parser.cpp" /* yacc.c:1257  */
+#line 1749 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 172: /* update_clause_commalist  */
-#line 143 "bison_parser.y" /* yacc.c:1257  */
+#line 138 "bison_parser.y" /* yacc.c:1257  */
       {
 	if ((((*yyvaluep).update_vec)) != NULL) {
 		for (auto ptr : *(((*yyvaluep).update_vec))) {
@@ -1756,47 +1758,47 @@ yydestruct (const char *yymsg, int yytype, YYSTYPE *yyvaluep, YYLTYPE *yylocatio
 	}
 	delete (((*yyvaluep).update_vec));
 }
-#line 1760 "bison_parser.cpp" /* yacc.c:1257  */
+#line 1762 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 173: /* update_clause  */
-#line 151 "bison_parser.y" /* yacc.c:1257  */
+#line 146 "bison_parser.y" /* yacc.c:1257  */
       { delete (((*yyvaluep).update_t)); }
-#line 1766 "bison_parser.cpp" /* yacc.c:1257  */
+#line 1768 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 174: /* select_statement  */
-#line 151 "bison_parser.y" /* yacc.c:1257  */
+#line 146 "bison_parser.y" /* yacc.c:1257  */
       { delete (((*yyvaluep).select_stmt)); }
-#line 1772 "bison_parser.cpp" /* yacc.c:1257  */
+#line 1774 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 175: /* select_with_paren  */
-#line 151 "bison_parser.y" /* yacc.c:1257  */
+#line 146 "bison_parser.y" /* yacc.c:1257  */
       { delete (((*yyvaluep).select_stmt)); }
-#line 1778 "bison_parser.cpp" /* yacc.c:1257  */
+#line 1780 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 176: /* select_no_paren  */
-#line 151 "bison_parser.y" /* yacc.c:1257  */
+#line 146 "bison_parser.y" /* yacc.c:1257  */
       { delete (((*yyvaluep).select_stmt)); }
-#line 1784 "bison_parser.cpp" /* yacc.c:1257  */
+#line 1786 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 178: /* select_clause  */
-#line 151 "bison_parser.y" /* yacc.c:1257  */
+#line 146 "bison_parser.y" /* yacc.c:1257  */
       { delete (((*yyvaluep).select_stmt)); }
-#line 1790 "bison_parser.cpp" /* yacc.c:1257  */
+#line 1792 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 179: /* opt_distinct  */
-#line 141 "bison_parser.y" /* yacc.c:1257  */
+#line 136 "bison_parser.y" /* yacc.c:1257  */
       { }
-#line 1796 "bison_parser.cpp" /* yacc.c:1257  */
+#line 1798 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 180: /* select_list  */
-#line 143 "bison_parser.y" /* yacc.c:1257  */
+#line 138 "bison_parser.y" /* yacc.c:1257  */
       {
 	if ((((*yyvaluep).expr_vec)) != NULL) {
 		for (auto ptr : *(((*yyvaluep).expr_vec))) {
@@ -1805,35 +1807,35 @@ yydestruct (const char *yymsg, int yytype, YYSTYPE *yyvaluep, YYLTYPE *yylocatio
 	}
 	delete (((*yyvaluep).expr_vec));
 }
-#line 1809 "bison_parser.cpp" /* yacc.c:1257  */
+#line 1811 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 181: /* from_clause  */
-#line 151 "bison_parser.y" /* yacc.c:1257  */
+#line 146 "bison_parser.y" /* yacc.c:1257  */
       { delete (((*yyvaluep).table)); }
-#line 1815 "bison_parser.cpp" /* yacc.c:1257  */
+#line 1817 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 182: /* opt_where  */
-#line 151 "bison_parser.y" /* yacc.c:1257  */
+#line 146 "bison_parser.y" /* yacc.c:1257  */
       { delete (((*yyvaluep).expr)); }
-#line 1821 "bison_parser.cpp" /* yacc.c:1257  */
+#line 1823 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 183: /* opt_group  */
-#line 151 "bison_parser.y" /* yacc.c:1257  */
+#line 146 "bison_parser.y" /* yacc.c:1257  */
       { delete (((*yyvaluep).group_t)); }
-#line 1827 "bison_parser.cpp" /* yacc.c:1257  */
+#line 1829 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 184: /* opt_having  */
-#line 151 "bison_parser.y" /* yacc.c:1257  */
+#line 146 "bison_parser.y" /* yacc.c:1257  */
       { delete (((*yyvaluep).expr)); }
-#line 1833 "bison_parser.cpp" /* yacc.c:1257  */
+#line 1835 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 185: /* opt_order  */
-#line 143 "bison_parser.y" /* yacc.c:1257  */
+#line 138 "bison_parser.y" /* yacc.c:1257  */
       {
 	if ((((*yyvaluep).order_vec)) != NULL) {
 		for (auto ptr : *(((*yyvaluep).order_vec))) {
@@ -1842,11 +1844,11 @@ yydestruct (const char *yymsg, int yytype, YYSTYPE *yyvaluep, YYLTYPE *yylocatio
 	}
 	delete (((*yyvaluep).order_vec));
 }
-#line 1846 "bison_parser.cpp" /* yacc.c:1257  */
+#line 1848 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 186: /* order_list  */
-#line 143 "bison_parser.y" /* yacc.c:1257  */
+#line 138 "bison_parser.y" /* yacc.c:1257  */
       {
 	if ((((*yyvaluep).order_vec)) != NULL) {
 		for (auto ptr : *(((*yyvaluep).order_vec))) {
@@ -1855,35 +1857,35 @@ yydestruct (const char *yymsg, int yytype, YYSTYPE *yyvaluep, YYLTYPE *yylocatio
 	}
 	delete (((*yyvaluep).order_vec));
 }
-#line 1859 "bison_parser.cpp" /* yacc.c:1257  */
+#line 1861 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 187: /* order_desc  */
-#line 151 "bison_parser.y" /* yacc.c:1257  */
+#line 146 "bison_parser.y" /* yacc.c:1257  */
       { delete (((*yyvaluep).order)); }
-#line 1865 "bison_parser.cpp" /* yacc.c:1257  */
+#line 1867 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 188: /* opt_order_type  */
-#line 141 "bison_parser.y" /* yacc.c:1257  */
+#line 136 "bison_parser.y" /* yacc.c:1257  */
       { }
-#line 1871 "bison_parser.cpp" /* yacc.c:1257  */
+#line 1873 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 189: /* opt_top  */
-#line 151 "bison_parser.y" /* yacc.c:1257  */
+#line 146 "bison_parser.y" /* yacc.c:1257  */
       { delete (((*yyvaluep).limit)); }
-#line 1877 "bison_parser.cpp" /* yacc.c:1257  */
+#line 1879 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 190: /* opt_limit  */
-#line 151 "bison_parser.y" /* yacc.c:1257  */
+#line 146 "bison_parser.y" /* yacc.c:1257  */
       { delete (((*yyvaluep).limit)); }
-#line 1883 "bison_parser.cpp" /* yacc.c:1257  */
+#line 1885 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 191: /* expr_list  */
-#line 143 "bison_parser.y" /* yacc.c:1257  */
+#line 138 "bison_parser.y" /* yacc.c:1257  */
       {
 	if ((((*yyvaluep).expr_vec)) != NULL) {
 		for (auto ptr : *(((*yyvaluep).expr_vec))) {
@@ -1892,11 +1894,11 @@ yydestruct (const char *yymsg, int yytype, YYSTYPE *yyvaluep, YYLTYPE *yylocatio
 	}
 	delete (((*yyvaluep).expr_vec));
 }
-#line 1896 "bison_parser.cpp" /* yacc.c:1257  */
+#line 1898 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 192: /* literal_list  */
-#line 143 "bison_parser.y" /* yacc.c:1257  */
+#line 138 "bison_parser.y" /* yacc.c:1257  */
       {
 	if ((((*yyvaluep).expr_vec)) != NULL) {
 		for (auto ptr : *(((*yyvaluep).expr_vec))) {
@@ -1905,143 +1907,143 @@ yydestruct (const char *yymsg, int yytype, YYSTYPE *yyvaluep, YYLTYPE *yylocatio
 	}
 	delete (((*yyvaluep).expr_vec));
 }
-#line 1909 "bison_parser.cpp" /* yacc.c:1257  */
+#line 1911 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 193: /* expr_alias  */
-#line 151 "bison_parser.y" /* yacc.c:1257  */
+#line 146 "bison_parser.y" /* yacc.c:1257  */
       { delete (((*yyvaluep).expr)); }
-#line 1915 "bison_parser.cpp" /* yacc.c:1257  */
+#line 1917 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 194: /* expr  */
-#line 151 "bison_parser.y" /* yacc.c:1257  */
+#line 146 "bison_parser.y" /* yacc.c:1257  */
       { delete (((*yyvaluep).expr)); }
-#line 1921 "bison_parser.cpp" /* yacc.c:1257  */
+#line 1923 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 195: /* operand  */
-#line 151 "bison_parser.y" /* yacc.c:1257  */
+#line 146 "bison_parser.y" /* yacc.c:1257  */
       { delete (((*yyvaluep).expr)); }
-#line 1927 "bison_parser.cpp" /* yacc.c:1257  */
+#line 1929 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 196: /* scalar_expr  */
-#line 151 "bison_parser.y" /* yacc.c:1257  */
+#line 146 "bison_parser.y" /* yacc.c:1257  */
       { delete (((*yyvaluep).expr)); }
-#line 1933 "bison_parser.cpp" /* yacc.c:1257  */
+#line 1935 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 197: /* unary_expr  */
-#line 151 "bison_parser.y" /* yacc.c:1257  */
+#line 146 "bison_parser.y" /* yacc.c:1257  */
       { delete (((*yyvaluep).expr)); }
-#line 1939 "bison_parser.cpp" /* yacc.c:1257  */
+#line 1941 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 198: /* binary_expr  */
-#line 151 "bison_parser.y" /* yacc.c:1257  */
+#line 146 "bison_parser.y" /* yacc.c:1257  */
       { delete (((*yyvaluep).expr)); }
-#line 1945 "bison_parser.cpp" /* yacc.c:1257  */
+#line 1947 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 199: /* logic_expr  */
-#line 151 "bison_parser.y" /* yacc.c:1257  */
+#line 146 "bison_parser.y" /* yacc.c:1257  */
       { delete (((*yyvaluep).expr)); }
-#line 1951 "bison_parser.cpp" /* yacc.c:1257  */
+#line 1953 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 200: /* in_expr  */
-#line 151 "bison_parser.y" /* yacc.c:1257  */
+#line 146 "bison_parser.y" /* yacc.c:1257  */
       { delete (((*yyvaluep).expr)); }
-#line 1957 "bison_parser.cpp" /* yacc.c:1257  */
+#line 1959 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 201: /* case_expr  */
-#line 151 "bison_parser.y" /* yacc.c:1257  */
+#line 146 "bison_parser.y" /* yacc.c:1257  */
       { delete (((*yyvaluep).expr)); }
-#line 1963 "bison_parser.cpp" /* yacc.c:1257  */
+#line 1965 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 202: /* exists_expr  */
-#line 151 "bison_parser.y" /* yacc.c:1257  */
+#line 146 "bison_parser.y" /* yacc.c:1257  */
       { delete (((*yyvaluep).expr)); }
-#line 1969 "bison_parser.cpp" /* yacc.c:1257  */
+#line 1971 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 203: /* comp_expr  */
-#line 151 "bison_parser.y" /* yacc.c:1257  */
+#line 146 "bison_parser.y" /* yacc.c:1257  */
       { delete (((*yyvaluep).expr)); }
-#line 1975 "bison_parser.cpp" /* yacc.c:1257  */
+#line 1977 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 204: /* function_expr  */
-#line 151 "bison_parser.y" /* yacc.c:1257  */
+#line 146 "bison_parser.y" /* yacc.c:1257  */
       { delete (((*yyvaluep).expr)); }
-#line 1981 "bison_parser.cpp" /* yacc.c:1257  */
+#line 1983 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 205: /* between_expr  */
-#line 151 "bison_parser.y" /* yacc.c:1257  */
+#line 146 "bison_parser.y" /* yacc.c:1257  */
       { delete (((*yyvaluep).expr)); }
-#line 1987 "bison_parser.cpp" /* yacc.c:1257  */
+#line 1989 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 206: /* column_name  */
-#line 151 "bison_parser.y" /* yacc.c:1257  */
+#line 146 "bison_parser.y" /* yacc.c:1257  */
       { delete (((*yyvaluep).expr)); }
-#line 1993 "bison_parser.cpp" /* yacc.c:1257  */
+#line 1995 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 207: /* literal  */
-#line 151 "bison_parser.y" /* yacc.c:1257  */
+#line 146 "bison_parser.y" /* yacc.c:1257  */
       { delete (((*yyvaluep).expr)); }
-#line 1999 "bison_parser.cpp" /* yacc.c:1257  */
+#line 2001 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 208: /* string_literal  */
-#line 151 "bison_parser.y" /* yacc.c:1257  */
+#line 146 "bison_parser.y" /* yacc.c:1257  */
       { delete (((*yyvaluep).expr)); }
-#line 2005 "bison_parser.cpp" /* yacc.c:1257  */
+#line 2007 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 209: /* num_literal  */
-#line 151 "bison_parser.y" /* yacc.c:1257  */
+#line 146 "bison_parser.y" /* yacc.c:1257  */
       { delete (((*yyvaluep).expr)); }
-#line 2011 "bison_parser.cpp" /* yacc.c:1257  */
+#line 2013 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 210: /* int_literal  */
-#line 151 "bison_parser.y" /* yacc.c:1257  */
+#line 146 "bison_parser.y" /* yacc.c:1257  */
       { delete (((*yyvaluep).expr)); }
-#line 2017 "bison_parser.cpp" /* yacc.c:1257  */
+#line 2019 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 211: /* star_expr  */
-#line 151 "bison_parser.y" /* yacc.c:1257  */
+#line 146 "bison_parser.y" /* yacc.c:1257  */
       { delete (((*yyvaluep).expr)); }
-#line 2023 "bison_parser.cpp" /* yacc.c:1257  */
+#line 2025 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 212: /* placeholder_expr  */
-#line 151 "bison_parser.y" /* yacc.c:1257  */
+#line 146 "bison_parser.y" /* yacc.c:1257  */
       { delete (((*yyvaluep).expr)); }
-#line 2029 "bison_parser.cpp" /* yacc.c:1257  */
+#line 2031 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 213: /* table_ref  */
-#line 151 "bison_parser.y" /* yacc.c:1257  */
+#line 146 "bison_parser.y" /* yacc.c:1257  */
       { delete (((*yyvaluep).table)); }
-#line 2035 "bison_parser.cpp" /* yacc.c:1257  */
+#line 2037 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 214: /* table_ref_atomic  */
-#line 151 "bison_parser.y" /* yacc.c:1257  */
+#line 146 "bison_parser.y" /* yacc.c:1257  */
       { delete (((*yyvaluep).table)); }
-#line 2041 "bison_parser.cpp" /* yacc.c:1257  */
+#line 2043 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 215: /* table_ref_commalist  */
-#line 143 "bison_parser.y" /* yacc.c:1257  */
+#line 138 "bison_parser.y" /* yacc.c:1257  */
       {
 	if ((((*yyvaluep).table_vec)) != NULL) {
 		for (auto ptr : *(((*yyvaluep).table_vec))) {
@@ -2050,65 +2052,65 @@ yydestruct (const char *yymsg, int yytype, YYSTYPE *yyvaluep, YYLTYPE *yylocatio
 	}
 	delete (((*yyvaluep).table_vec));
 }
-#line 2054 "bison_parser.cpp" /* yacc.c:1257  */
+#line 2056 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 216: /* table_ref_name  */
-#line 151 "bison_parser.y" /* yacc.c:1257  */
+#line 146 "bison_parser.y" /* yacc.c:1257  */
       { delete (((*yyvaluep).table)); }
-#line 2060 "bison_parser.cpp" /* yacc.c:1257  */
+#line 2062 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 217: /* table_ref_name_no_alias  */
-#line 151 "bison_parser.y" /* yacc.c:1257  */
+#line 146 "bison_parser.y" /* yacc.c:1257  */
       { delete (((*yyvaluep).table)); }
-#line 2066 "bison_parser.cpp" /* yacc.c:1257  */
+#line 2068 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 218: /* table_name  */
-#line 142 "bison_parser.y" /* yacc.c:1257  */
+#line 137 "bison_parser.y" /* yacc.c:1257  */
       { free( (((*yyvaluep).sval)) ); }
-#line 2072 "bison_parser.cpp" /* yacc.c:1257  */
+#line 2074 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 219: /* alias  */
-#line 142 "bison_parser.y" /* yacc.c:1257  */
+#line 137 "bison_parser.y" /* yacc.c:1257  */
       { free( (((*yyvaluep).sval)) ); }
-#line 2078 "bison_parser.cpp" /* yacc.c:1257  */
+#line 2080 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 220: /* opt_alias  */
-#line 142 "bison_parser.y" /* yacc.c:1257  */
+#line 137 "bison_parser.y" /* yacc.c:1257  */
       { free( (((*yyvaluep).sval)) ); }
-#line 2084 "bison_parser.cpp" /* yacc.c:1257  */
+#line 2086 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 221: /* join_clause  */
-#line 151 "bison_parser.y" /* yacc.c:1257  */
+#line 146 "bison_parser.y" /* yacc.c:1257  */
       { delete (((*yyvaluep).table)); }
-#line 2090 "bison_parser.cpp" /* yacc.c:1257  */
+#line 2092 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 222: /* opt_join_type  */
-#line 141 "bison_parser.y" /* yacc.c:1257  */
+#line 136 "bison_parser.y" /* yacc.c:1257  */
       { }
-#line 2096 "bison_parser.cpp" /* yacc.c:1257  */
+#line 2098 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 223: /* join_table  */
-#line 151 "bison_parser.y" /* yacc.c:1257  */
+#line 146 "bison_parser.y" /* yacc.c:1257  */
       { delete (((*yyvaluep).table)); }
-#line 2102 "bison_parser.cpp" /* yacc.c:1257  */
+#line 2104 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 224: /* join_condition  */
-#line 151 "bison_parser.y" /* yacc.c:1257  */
+#line 146 "bison_parser.y" /* yacc.c:1257  */
       { delete (((*yyvaluep).expr)); }
-#line 2108 "bison_parser.cpp" /* yacc.c:1257  */
+#line 2110 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
     case 226: /* ident_commalist  */
-#line 143 "bison_parser.y" /* yacc.c:1257  */
+#line 138 "bison_parser.y" /* yacc.c:1257  */
       {
 	if ((((*yyvaluep).str_vec)) != NULL) {
 		for (auto ptr : *(((*yyvaluep).str_vec))) {
@@ -2117,7 +2119,7 @@ yydestruct (const char *yymsg, int yytype, YYSTYPE *yyvaluep, YYLTYPE *yylocatio
 	}
 	delete (((*yyvaluep).str_vec));
 }
-#line 2121 "bison_parser.cpp" /* yacc.c:1257  */
+#line 2123 "bison_parser.cpp" /* yacc.c:1257  */
         break;
 
 
@@ -2135,7 +2137,7 @@ yydestruct (const char *yymsg, int yytype, YYSTYPE *yyvaluep, YYLTYPE *yylocatio
 `----------*/
 
 int
-yyparse (hsql::SQLParserResult** result, yyscan_t scanner)
+yyparse (hsql::SQLParserResult* result, yyscan_t scanner)
 {
 /* The lookahead symbol.  */
 int yychar;
@@ -2225,7 +2227,7 @@ YYLTYPE yylloc = yyloc_default;
   yychar = YYEMPTY; /* Cause a token to be read.  */
 
 /* User initialization code.  */
-#line 78 "bison_parser.y" /* yacc.c:1429  */
+#line 73 "bison_parser.y" /* yacc.c:1429  */
 {
 	// Initialize
 	yylloc.first_column = 0;
@@ -2236,7 +2238,7 @@ YYLTYPE yylloc = yyloc_default;
 	yylloc.placeholder_id = 0;
 }
 
-#line 2240 "bison_parser.cpp" /* yacc.c:1429  */
+#line 2242 "bison_parser.cpp" /* yacc.c:1429  */
   yylsp[0] = yylloc;
   goto yysetstate;
 
@@ -2423,174 +2425,182 @@ yyreduce:
   switch (yyn)
     {
         case 2:
-#line 245 "bison_parser.y" /* yacc.c:1646  */
+#line 240 "bison_parser.y" /* yacc.c:1646  */
     {
-			*result = (yyvsp[-1].stmt_list);
+		  for (SQLStatement* stmt : *(yyvsp[-1].stmt_vec)) {
+		    // Transfers ownership of the statement.
+		  	result->addStatement(stmt);
+		  }
+		  delete (yyvsp[-1].stmt_vec);
 		}
-#line 2431 "bison_parser.cpp" /* yacc.c:1646  */
-    break;
-
-  case 3:
-#line 252 "bison_parser.y" /* yacc.c:1646  */
-    { (yyval.stmt_list) = new SQLParserResult((yyvsp[0].statement)); }
 #line 2437 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
-  case 4:
-#line 253 "bison_parser.y" /* yacc.c:1646  */
-    { (yyvsp[-2].stmt_list)->addStatement((yyvsp[0].statement)); (yyval.stmt_list) = (yyvsp[-2].stmt_list); }
+  case 3:
+#line 251 "bison_parser.y" /* yacc.c:1646  */
+    { (yyval.stmt_vec) = new std::vector<SQLStatement*>(); (yyval.stmt_vec)->push_back((yyvsp[0].statement)); }
 #line 2443 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
+  case 4:
+#line 252 "bison_parser.y" /* yacc.c:1646  */
+    { (yyvsp[-2].stmt_vec)->push_back((yyvsp[0].statement)); (yyval.stmt_vec) = (yyvsp[-2].stmt_vec); }
+#line 2449 "bison_parser.cpp" /* yacc.c:1646  */
+    break;
+
   case 5:
-#line 257 "bison_parser.y" /* yacc.c:1646  */
+#line 256 "bison_parser.y" /* yacc.c:1646  */
     {
 			(yyvsp[0].prep_stmt)->setPlaceholders(yyloc.placeholder_list);
 			yyloc.placeholder_list.clear();
 			(yyval.statement) = (yyvsp[0].prep_stmt);
 		}
-#line 2453 "bison_parser.cpp" /* yacc.c:1646  */
-    break;
-
-  case 7:
-#line 267 "bison_parser.y" /* yacc.c:1646  */
-    { (yyval.statement) = (yyvsp[0].select_stmt); }
 #line 2459 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
-  case 8:
-#line 268 "bison_parser.y" /* yacc.c:1646  */
-    { (yyval.statement) = (yyvsp[0].import_stmt); }
+  case 7:
+#line 266 "bison_parser.y" /* yacc.c:1646  */
+    { (yyval.statement) = (yyvsp[0].select_stmt); }
 #line 2465 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
-  case 9:
-#line 269 "bison_parser.y" /* yacc.c:1646  */
-    { (yyval.statement) = (yyvsp[0].create_stmt); }
+  case 8:
+#line 267 "bison_parser.y" /* yacc.c:1646  */
+    { (yyval.statement) = (yyvsp[0].import_stmt); }
 #line 2471 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
-  case 10:
-#line 270 "bison_parser.y" /* yacc.c:1646  */
-    { (yyval.statement) = (yyvsp[0].insert_stmt); }
+  case 9:
+#line 268 "bison_parser.y" /* yacc.c:1646  */
+    { (yyval.statement) = (yyvsp[0].create_stmt); }
 #line 2477 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
-  case 11:
-#line 271 "bison_parser.y" /* yacc.c:1646  */
-    { (yyval.statement) = (yyvsp[0].delete_stmt); }
+  case 10:
+#line 269 "bison_parser.y" /* yacc.c:1646  */
+    { (yyval.statement) = (yyvsp[0].insert_stmt); }
 #line 2483 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
-  case 12:
-#line 272 "bison_parser.y" /* yacc.c:1646  */
+  case 11:
+#line 270 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.statement) = (yyvsp[0].delete_stmt); }
 #line 2489 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
-  case 13:
-#line 273 "bison_parser.y" /* yacc.c:1646  */
-    { (yyval.statement) = (yyvsp[0].update_stmt); }
+  case 12:
+#line 271 "bison_parser.y" /* yacc.c:1646  */
+    { (yyval.statement) = (yyvsp[0].delete_stmt); }
 #line 2495 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
-  case 14:
-#line 274 "bison_parser.y" /* yacc.c:1646  */
-    { (yyval.statement) = (yyvsp[0].drop_stmt); }
+  case 13:
+#line 272 "bison_parser.y" /* yacc.c:1646  */
+    { (yyval.statement) = (yyvsp[0].update_stmt); }
 #line 2501 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
-  case 15:
-#line 275 "bison_parser.y" /* yacc.c:1646  */
-    { (yyval.statement) = (yyvsp[0].exec_stmt); }
+  case 14:
+#line 273 "bison_parser.y" /* yacc.c:1646  */
+    { (yyval.statement) = (yyvsp[0].drop_stmt); }
 #line 2507 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
+  case 15:
+#line 274 "bison_parser.y" /* yacc.c:1646  */
+    { (yyval.statement) = (yyvsp[0].exec_stmt); }
+#line 2513 "bison_parser.cpp" /* yacc.c:1646  */
+    break;
+
   case 16:
-#line 283 "bison_parser.y" /* yacc.c:1646  */
+#line 282 "bison_parser.y" /* yacc.c:1646  */
     {
 			(yyval.prep_stmt) = new PrepareStatement();
 			(yyval.prep_stmt)->name = (yyvsp[-2].sval);
 			(yyval.prep_stmt)->query = new SQLParserResult((yyvsp[0].statement));
 		}
-#line 2517 "bison_parser.cpp" /* yacc.c:1646  */
+#line 2523 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 17:
-#line 288 "bison_parser.y" /* yacc.c:1646  */
+#line 287 "bison_parser.y" /* yacc.c:1646  */
     {
 			(yyval.prep_stmt) = new PrepareStatement();
 			(yyval.prep_stmt)->name = (yyvsp[-4].sval);
-			(yyval.prep_stmt)->query = (yyvsp[-2].stmt_list);
+			(yyval.prep_stmt)->query = new SQLParserResult();
+		  for (SQLStatement* stmt : *(yyvsp[-2].stmt_vec)) {
+		  	(yyval.prep_stmt)->query->addStatement(stmt);
+		  }
+		  delete (yyvsp[-2].stmt_vec);
 		}
-#line 2527 "bison_parser.cpp" /* yacc.c:1646  */
+#line 2537 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 18:
-#line 296 "bison_parser.y" /* yacc.c:1646  */
+#line 299 "bison_parser.y" /* yacc.c:1646  */
     {
 			(yyval.exec_stmt) = new ExecuteStatement();
 			(yyval.exec_stmt)->name = (yyvsp[0].sval);
 		}
-#line 2536 "bison_parser.cpp" /* yacc.c:1646  */
+#line 2546 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 19:
-#line 300 "bison_parser.y" /* yacc.c:1646  */
+#line 303 "bison_parser.y" /* yacc.c:1646  */
     {
 			(yyval.exec_stmt) = new ExecuteStatement();
 			(yyval.exec_stmt)->name = (yyvsp[-3].sval);
 			(yyval.exec_stmt)->parameters = (yyvsp[-1].expr_vec);
 		}
-#line 2546 "bison_parser.cpp" /* yacc.c:1646  */
+#line 2556 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 20:
-#line 312 "bison_parser.y" /* yacc.c:1646  */
+#line 315 "bison_parser.y" /* yacc.c:1646  */
     {
 			(yyval.import_stmt) = new ImportStatement((ImportStatement::ImportType) (yyvsp[-4].uval));
 			(yyval.import_stmt)->filePath = (yyvsp[-2].sval);
 			(yyval.import_stmt)->tableName = (yyvsp[0].sval);
 		}
-#line 2556 "bison_parser.cpp" /* yacc.c:1646  */
+#line 2566 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 21:
-#line 320 "bison_parser.y" /* yacc.c:1646  */
+#line 323 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.uval) = ImportStatement::kImportCSV; }
-#line 2562 "bison_parser.cpp" /* yacc.c:1646  */
+#line 2572 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 22:
-#line 324 "bison_parser.y" /* yacc.c:1646  */
+#line 327 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.sval) = strdup((yyvsp[0].expr)->name); delete (yyvsp[0].expr); }
-#line 2568 "bison_parser.cpp" /* yacc.c:1646  */
+#line 2578 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 23:
-#line 334 "bison_parser.y" /* yacc.c:1646  */
+#line 337 "bison_parser.y" /* yacc.c:1646  */
     {
 			(yyval.create_stmt) = new CreateStatement(CreateStatement::kTableFromTbl);
 			(yyval.create_stmt)->ifNotExists = (yyvsp[-5].bval);
 			(yyval.create_stmt)->tableName = (yyvsp[-4].sval);
 			(yyval.create_stmt)->filePath = (yyvsp[0].sval);
 		}
-#line 2579 "bison_parser.cpp" /* yacc.c:1646  */
+#line 2589 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 24:
-#line 340 "bison_parser.y" /* yacc.c:1646  */
+#line 343 "bison_parser.y" /* yacc.c:1646  */
     {
 			(yyval.create_stmt) = new CreateStatement(CreateStatement::kTable);
 			(yyval.create_stmt)->ifNotExists = (yyvsp[-4].bval);
 			(yyval.create_stmt)->tableName = (yyvsp[-3].sval);
 			(yyval.create_stmt)->columns = (yyvsp[-1].column_vec);
 		}
-#line 2590 "bison_parser.cpp" /* yacc.c:1646  */
+#line 2600 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 25:
-#line 346 "bison_parser.y" /* yacc.c:1646  */
+#line 349 "bison_parser.y" /* yacc.c:1646  */
     {
 			(yyval.create_stmt) = new CreateStatement(CreateStatement::kView);
 			(yyval.create_stmt)->ifNotExists = (yyvsp[-4].bval);
@@ -2598,192 +2608,192 @@ yyreduce:
 			(yyval.create_stmt)->viewColumns = (yyvsp[-2].str_vec);
 			(yyval.create_stmt)->select = (yyvsp[0].select_stmt);
 		}
-#line 2602 "bison_parser.cpp" /* yacc.c:1646  */
+#line 2612 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 26:
-#line 356 "bison_parser.y" /* yacc.c:1646  */
+#line 359 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.bval) = true; }
-#line 2608 "bison_parser.cpp" /* yacc.c:1646  */
+#line 2618 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 27:
-#line 357 "bison_parser.y" /* yacc.c:1646  */
+#line 360 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.bval) = false; }
-#line 2614 "bison_parser.cpp" /* yacc.c:1646  */
+#line 2624 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 28:
-#line 361 "bison_parser.y" /* yacc.c:1646  */
+#line 364 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.column_vec) = new std::vector<ColumnDefinition*>(); (yyval.column_vec)->push_back((yyvsp[0].column_t)); }
-#line 2620 "bison_parser.cpp" /* yacc.c:1646  */
+#line 2630 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 29:
-#line 362 "bison_parser.y" /* yacc.c:1646  */
+#line 365 "bison_parser.y" /* yacc.c:1646  */
     { (yyvsp[-2].column_vec)->push_back((yyvsp[0].column_t)); (yyval.column_vec) = (yyvsp[-2].column_vec); }
-#line 2626 "bison_parser.cpp" /* yacc.c:1646  */
+#line 2636 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 30:
-#line 366 "bison_parser.y" /* yacc.c:1646  */
+#line 369 "bison_parser.y" /* yacc.c:1646  */
     {
 			(yyval.column_t) = new ColumnDefinition((yyvsp[-1].sval), (ColumnDefinition::DataType) (yyvsp[0].uval));
 		}
-#line 2634 "bison_parser.cpp" /* yacc.c:1646  */
+#line 2644 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 31:
-#line 373 "bison_parser.y" /* yacc.c:1646  */
+#line 376 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.uval) = ColumnDefinition::INT; }
-#line 2640 "bison_parser.cpp" /* yacc.c:1646  */
+#line 2650 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 32:
-#line 374 "bison_parser.y" /* yacc.c:1646  */
+#line 377 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.uval) = ColumnDefinition::INT; }
-#line 2646 "bison_parser.cpp" /* yacc.c:1646  */
+#line 2656 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 33:
-#line 375 "bison_parser.y" /* yacc.c:1646  */
+#line 378 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.uval) = ColumnDefinition::DOUBLE; }
-#line 2652 "bison_parser.cpp" /* yacc.c:1646  */
+#line 2662 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 34:
-#line 376 "bison_parser.y" /* yacc.c:1646  */
+#line 379 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.uval) = ColumnDefinition::TEXT; }
-#line 2658 "bison_parser.cpp" /* yacc.c:1646  */
+#line 2668 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 35:
-#line 386 "bison_parser.y" /* yacc.c:1646  */
+#line 389 "bison_parser.y" /* yacc.c:1646  */
     {
 			(yyval.drop_stmt) = new DropStatement(DropStatement::kTable);
 			(yyval.drop_stmt)->name = (yyvsp[0].sval);
 		}
-#line 2667 "bison_parser.cpp" /* yacc.c:1646  */
+#line 2677 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 36:
-#line 390 "bison_parser.y" /* yacc.c:1646  */
+#line 393 "bison_parser.y" /* yacc.c:1646  */
     {
 			(yyval.drop_stmt) = new DropStatement(DropStatement::kView);
 			(yyval.drop_stmt)->name = (yyvsp[0].sval);
 		}
-#line 2676 "bison_parser.cpp" /* yacc.c:1646  */
+#line 2686 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 37:
-#line 394 "bison_parser.y" /* yacc.c:1646  */
+#line 397 "bison_parser.y" /* yacc.c:1646  */
     {
 			(yyval.drop_stmt) = new DropStatement(DropStatement::kPreparedStatement);
 			(yyval.drop_stmt)->name = (yyvsp[0].sval);
 		}
-#line 2685 "bison_parser.cpp" /* yacc.c:1646  */
+#line 2695 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 38:
-#line 406 "bison_parser.y" /* yacc.c:1646  */
+#line 409 "bison_parser.y" /* yacc.c:1646  */
     {
 			(yyval.delete_stmt) = new DeleteStatement();
 			(yyval.delete_stmt)->tableName = (yyvsp[-1].sval);
 			(yyval.delete_stmt)->expr = (yyvsp[0].expr);
 		}
-#line 2695 "bison_parser.cpp" /* yacc.c:1646  */
+#line 2705 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 39:
-#line 414 "bison_parser.y" /* yacc.c:1646  */
+#line 417 "bison_parser.y" /* yacc.c:1646  */
     {
 			(yyval.delete_stmt) = new DeleteStatement();
 			(yyval.delete_stmt)->tableName = (yyvsp[0].sval);
 		}
-#line 2704 "bison_parser.cpp" /* yacc.c:1646  */
+#line 2714 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 40:
-#line 426 "bison_parser.y" /* yacc.c:1646  */
+#line 429 "bison_parser.y" /* yacc.c:1646  */
     {
 			(yyval.insert_stmt) = new InsertStatement(InsertStatement::kInsertValues);
 			(yyval.insert_stmt)->tableName = (yyvsp[-5].sval);
 			(yyval.insert_stmt)->columns = (yyvsp[-4].str_vec);
 			(yyval.insert_stmt)->values = (yyvsp[-1].expr_vec);
 		}
-#line 2715 "bison_parser.cpp" /* yacc.c:1646  */
+#line 2725 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 41:
-#line 432 "bison_parser.y" /* yacc.c:1646  */
+#line 435 "bison_parser.y" /* yacc.c:1646  */
     {
 			(yyval.insert_stmt) = new InsertStatement(InsertStatement::kInsertSelect);
 			(yyval.insert_stmt)->tableName = (yyvsp[-2].sval);
 			(yyval.insert_stmt)->columns = (yyvsp[-1].str_vec);
 			(yyval.insert_stmt)->select = (yyvsp[0].select_stmt);
 		}
-#line 2726 "bison_parser.cpp" /* yacc.c:1646  */
+#line 2736 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 42:
-#line 442 "bison_parser.y" /* yacc.c:1646  */
+#line 445 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.str_vec) = (yyvsp[-1].str_vec); }
-#line 2732 "bison_parser.cpp" /* yacc.c:1646  */
+#line 2742 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 43:
-#line 443 "bison_parser.y" /* yacc.c:1646  */
+#line 446 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.str_vec) = NULL; }
-#line 2738 "bison_parser.cpp" /* yacc.c:1646  */
+#line 2748 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 44:
-#line 453 "bison_parser.y" /* yacc.c:1646  */
+#line 456 "bison_parser.y" /* yacc.c:1646  */
     {
 		(yyval.update_stmt) = new UpdateStatement();
 		(yyval.update_stmt)->table = (yyvsp[-3].table);
 		(yyval.update_stmt)->updates = (yyvsp[-1].update_vec);
 		(yyval.update_stmt)->where = (yyvsp[0].expr);
 	}
-#line 2749 "bison_parser.cpp" /* yacc.c:1646  */
+#line 2759 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 45:
-#line 462 "bison_parser.y" /* yacc.c:1646  */
+#line 465 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.update_vec) = new std::vector<UpdateClause*>(); (yyval.update_vec)->push_back((yyvsp[0].update_t)); }
-#line 2755 "bison_parser.cpp" /* yacc.c:1646  */
+#line 2765 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 46:
-#line 463 "bison_parser.y" /* yacc.c:1646  */
+#line 466 "bison_parser.y" /* yacc.c:1646  */
     { (yyvsp[-2].update_vec)->push_back((yyvsp[0].update_t)); (yyval.update_vec) = (yyvsp[-2].update_vec); }
-#line 2761 "bison_parser.cpp" /* yacc.c:1646  */
+#line 2771 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 47:
-#line 467 "bison_parser.y" /* yacc.c:1646  */
+#line 470 "bison_parser.y" /* yacc.c:1646  */
     {
 			(yyval.update_t) = new UpdateClause();
 			(yyval.update_t)->column = (yyvsp[-2].sval);
 			(yyval.update_t)->value = (yyvsp[0].expr);
 		}
-#line 2771 "bison_parser.cpp" /* yacc.c:1646  */
+#line 2781 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 50:
-#line 484 "bison_parser.y" /* yacc.c:1646  */
+#line 487 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.select_stmt) = (yyvsp[-1].select_stmt); }
-#line 2777 "bison_parser.cpp" /* yacc.c:1646  */
+#line 2787 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 51:
-#line 485 "bison_parser.y" /* yacc.c:1646  */
+#line 488 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.select_stmt) = (yyvsp[-1].select_stmt); }
-#line 2783 "bison_parser.cpp" /* yacc.c:1646  */
+#line 2793 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 52:
-#line 489 "bison_parser.y" /* yacc.c:1646  */
+#line 492 "bison_parser.y" /* yacc.c:1646  */
     {
 			(yyval.select_stmt) = (yyvsp[-2].select_stmt);
 			(yyval.select_stmt)->order = (yyvsp[-1].order_vec);
@@ -2794,11 +2804,11 @@ yyreduce:
 				(yyval.select_stmt)->limit = (yyvsp[0].limit);
 			}
 		}
-#line 2798 "bison_parser.cpp" /* yacc.c:1646  */
+#line 2808 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 53:
-#line 499 "bison_parser.y" /* yacc.c:1646  */
+#line 502 "bison_parser.y" /* yacc.c:1646  */
     {
 			// TODO: allow multiple unions (through linked list)
 			// TODO: capture type of set_operator
@@ -2813,11 +2823,11 @@ yyreduce:
 				(yyval.select_stmt)->limit = (yyvsp[0].limit);
 			}
 		}
-#line 2817 "bison_parser.cpp" /* yacc.c:1646  */
+#line 2827 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 54:
-#line 513 "bison_parser.y" /* yacc.c:1646  */
+#line 516 "bison_parser.y" /* yacc.c:1646  */
     {
 			(yyval.select_stmt) = (yyvsp[-4].select_stmt);
 			(yyval.select_stmt)->unionSelect = (yyvsp[-2].select_stmt);
@@ -2829,11 +2839,11 @@ yyreduce:
 				(yyval.select_stmt)->limit = (yyvsp[0].limit);
 			}
 		}
-#line 2833 "bison_parser.cpp" /* yacc.c:1646  */
+#line 2843 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 58:
-#line 533 "bison_parser.y" /* yacc.c:1646  */
+#line 536 "bison_parser.y" /* yacc.c:1646  */
     {
 			(yyval.select_stmt) = new SelectStatement();
 			(yyval.select_stmt)->limit = (yyvsp[-5].limit);
@@ -2843,465 +2853,465 @@ yyreduce:
 			(yyval.select_stmt)->whereClause = (yyvsp[-1].expr);
 			(yyval.select_stmt)->groupBy = (yyvsp[0].group_t);
 		}
-#line 2847 "bison_parser.cpp" /* yacc.c:1646  */
+#line 2857 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 59:
-#line 545 "bison_parser.y" /* yacc.c:1646  */
+#line 548 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.bval) = true; }
-#line 2853 "bison_parser.cpp" /* yacc.c:1646  */
+#line 2863 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 60:
-#line 546 "bison_parser.y" /* yacc.c:1646  */
+#line 549 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.bval) = false; }
-#line 2859 "bison_parser.cpp" /* yacc.c:1646  */
+#line 2869 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 62:
-#line 554 "bison_parser.y" /* yacc.c:1646  */
+#line 557 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.table) = (yyvsp[0].table); }
-#line 2865 "bison_parser.cpp" /* yacc.c:1646  */
+#line 2875 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 63:
-#line 559 "bison_parser.y" /* yacc.c:1646  */
+#line 562 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.expr) = (yyvsp[0].expr); }
-#line 2871 "bison_parser.cpp" /* yacc.c:1646  */
+#line 2881 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 64:
-#line 560 "bison_parser.y" /* yacc.c:1646  */
+#line 563 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.expr) = NULL; }
-#line 2877 "bison_parser.cpp" /* yacc.c:1646  */
+#line 2887 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 65:
-#line 564 "bison_parser.y" /* yacc.c:1646  */
+#line 567 "bison_parser.y" /* yacc.c:1646  */
     {
 			(yyval.group_t) = new GroupByDescription();
 			(yyval.group_t)->columns = (yyvsp[-1].expr_vec);
 			(yyval.group_t)->having = (yyvsp[0].expr);
 		}
-#line 2887 "bison_parser.cpp" /* yacc.c:1646  */
+#line 2897 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 66:
-#line 569 "bison_parser.y" /* yacc.c:1646  */
+#line 572 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.group_t) = NULL; }
-#line 2893 "bison_parser.cpp" /* yacc.c:1646  */
+#line 2903 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 67:
-#line 573 "bison_parser.y" /* yacc.c:1646  */
+#line 576 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.expr) = (yyvsp[0].expr); }
-#line 2899 "bison_parser.cpp" /* yacc.c:1646  */
+#line 2909 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 68:
-#line 574 "bison_parser.y" /* yacc.c:1646  */
+#line 577 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.expr) = NULL; }
-#line 2905 "bison_parser.cpp" /* yacc.c:1646  */
+#line 2915 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 69:
-#line 577 "bison_parser.y" /* yacc.c:1646  */
+#line 580 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.order_vec) = (yyvsp[0].order_vec); }
-#line 2911 "bison_parser.cpp" /* yacc.c:1646  */
+#line 2921 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 70:
-#line 578 "bison_parser.y" /* yacc.c:1646  */
+#line 581 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.order_vec) = NULL; }
-#line 2917 "bison_parser.cpp" /* yacc.c:1646  */
+#line 2927 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 71:
-#line 582 "bison_parser.y" /* yacc.c:1646  */
+#line 585 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.order_vec) = new std::vector<OrderDescription*>(); (yyval.order_vec)->push_back((yyvsp[0].order)); }
-#line 2923 "bison_parser.cpp" /* yacc.c:1646  */
+#line 2933 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 72:
-#line 583 "bison_parser.y" /* yacc.c:1646  */
+#line 586 "bison_parser.y" /* yacc.c:1646  */
     { (yyvsp[-2].order_vec)->push_back((yyvsp[0].order)); (yyval.order_vec) = (yyvsp[-2].order_vec); }
-#line 2929 "bison_parser.cpp" /* yacc.c:1646  */
+#line 2939 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 73:
-#line 587 "bison_parser.y" /* yacc.c:1646  */
+#line 590 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.order) = new OrderDescription((yyvsp[0].order_type), (yyvsp[-1].expr)); }
-#line 2935 "bison_parser.cpp" /* yacc.c:1646  */
+#line 2945 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 74:
-#line 591 "bison_parser.y" /* yacc.c:1646  */
+#line 594 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.order_type) = kOrderAsc; }
-#line 2941 "bison_parser.cpp" /* yacc.c:1646  */
+#line 2951 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 75:
-#line 592 "bison_parser.y" /* yacc.c:1646  */
+#line 595 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.order_type) = kOrderDesc; }
-#line 2947 "bison_parser.cpp" /* yacc.c:1646  */
+#line 2957 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 76:
-#line 593 "bison_parser.y" /* yacc.c:1646  */
+#line 596 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.order_type) = kOrderAsc; }
-#line 2953 "bison_parser.cpp" /* yacc.c:1646  */
+#line 2963 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 77:
-#line 599 "bison_parser.y" /* yacc.c:1646  */
+#line 602 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.limit) = new LimitDescription((yyvsp[0].expr)->ival, kNoOffset); delete (yyvsp[0].expr); }
-#line 2959 "bison_parser.cpp" /* yacc.c:1646  */
+#line 2969 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 78:
-#line 600 "bison_parser.y" /* yacc.c:1646  */
+#line 603 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.limit) = NULL; }
-#line 2965 "bison_parser.cpp" /* yacc.c:1646  */
+#line 2975 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 79:
-#line 604 "bison_parser.y" /* yacc.c:1646  */
+#line 607 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.limit) = new LimitDescription((yyvsp[0].expr)->ival, kNoOffset); delete (yyvsp[0].expr); }
-#line 2971 "bison_parser.cpp" /* yacc.c:1646  */
+#line 2981 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 80:
-#line 605 "bison_parser.y" /* yacc.c:1646  */
+#line 608 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.limit) = new LimitDescription((yyvsp[-2].expr)->ival, (yyvsp[0].expr)->ival); delete (yyvsp[-2].expr); delete (yyvsp[0].expr); }
-#line 2977 "bison_parser.cpp" /* yacc.c:1646  */
+#line 2987 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 81:
-#line 606 "bison_parser.y" /* yacc.c:1646  */
+#line 609 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.limit) = NULL; }
-#line 2983 "bison_parser.cpp" /* yacc.c:1646  */
+#line 2993 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 82:
-#line 613 "bison_parser.y" /* yacc.c:1646  */
+#line 616 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.expr_vec) = new std::vector<Expr*>(); (yyval.expr_vec)->push_back((yyvsp[0].expr)); }
-#line 2989 "bison_parser.cpp" /* yacc.c:1646  */
+#line 2999 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 83:
-#line 614 "bison_parser.y" /* yacc.c:1646  */
+#line 617 "bison_parser.y" /* yacc.c:1646  */
     { (yyvsp[-2].expr_vec)->push_back((yyvsp[0].expr)); (yyval.expr_vec) = (yyvsp[-2].expr_vec); }
-#line 2995 "bison_parser.cpp" /* yacc.c:1646  */
+#line 3005 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 84:
-#line 618 "bison_parser.y" /* yacc.c:1646  */
+#line 621 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.expr_vec) = new std::vector<Expr*>(); (yyval.expr_vec)->push_back((yyvsp[0].expr)); }
-#line 3001 "bison_parser.cpp" /* yacc.c:1646  */
+#line 3011 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 85:
-#line 619 "bison_parser.y" /* yacc.c:1646  */
+#line 622 "bison_parser.y" /* yacc.c:1646  */
     { (yyvsp[-2].expr_vec)->push_back((yyvsp[0].expr)); (yyval.expr_vec) = (yyvsp[-2].expr_vec); }
-#line 3007 "bison_parser.cpp" /* yacc.c:1646  */
+#line 3017 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 86:
-#line 623 "bison_parser.y" /* yacc.c:1646  */
+#line 626 "bison_parser.y" /* yacc.c:1646  */
     {
 			(yyval.expr) = (yyvsp[-1].expr);
 			(yyval.expr)->alias = (yyvsp[0].sval);
 		}
-#line 3016 "bison_parser.cpp" /* yacc.c:1646  */
+#line 3026 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 93:
-#line 639 "bison_parser.y" /* yacc.c:1646  */
+#line 642 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.expr) = (yyvsp[-1].expr); }
-#line 3022 "bison_parser.cpp" /* yacc.c:1646  */
+#line 3032 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 98:
-#line 644 "bison_parser.y" /* yacc.c:1646  */
+#line 647 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.expr) = Expr::makeSelect((yyvsp[-1].select_stmt)); }
-#line 3028 "bison_parser.cpp" /* yacc.c:1646  */
+#line 3038 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 102:
-#line 654 "bison_parser.y" /* yacc.c:1646  */
-    { (yyval.expr) = Expr::makeOpUnary(Expr::UMINUS, (yyvsp[0].expr)); }
-#line 3034 "bison_parser.cpp" /* yacc.c:1646  */
+#line 657 "bison_parser.y" /* yacc.c:1646  */
+    { (yyval.expr) = Expr::makeOpUnary(kOpMinus, (yyvsp[0].expr)); }
+#line 3044 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 103:
-#line 655 "bison_parser.y" /* yacc.c:1646  */
-    { (yyval.expr) = Expr::makeOpUnary(Expr::NOT, (yyvsp[0].expr)); }
-#line 3040 "bison_parser.cpp" /* yacc.c:1646  */
+#line 658 "bison_parser.y" /* yacc.c:1646  */
+    { (yyval.expr) = Expr::makeOpUnary(kOpNot, (yyvsp[0].expr)); }
+#line 3050 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 105:
-#line 660 "bison_parser.y" /* yacc.c:1646  */
+#line 663 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.expr) = Expr::makeOpBinary((yyvsp[-2].expr), '-', (yyvsp[0].expr)); }
-#line 3046 "bison_parser.cpp" /* yacc.c:1646  */
+#line 3056 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 106:
-#line 661 "bison_parser.y" /* yacc.c:1646  */
+#line 664 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.expr) = Expr::makeOpBinary((yyvsp[-2].expr), '+', (yyvsp[0].expr)); }
-#line 3052 "bison_parser.cpp" /* yacc.c:1646  */
+#line 3062 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 107:
-#line 662 "bison_parser.y" /* yacc.c:1646  */
+#line 665 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.expr) = Expr::makeOpBinary((yyvsp[-2].expr), '/', (yyvsp[0].expr)); }
-#line 3058 "bison_parser.cpp" /* yacc.c:1646  */
+#line 3068 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 108:
-#line 663 "bison_parser.y" /* yacc.c:1646  */
+#line 666 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.expr) = Expr::makeOpBinary((yyvsp[-2].expr), '*', (yyvsp[0].expr)); }
-#line 3064 "bison_parser.cpp" /* yacc.c:1646  */
+#line 3074 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 109:
-#line 664 "bison_parser.y" /* yacc.c:1646  */
+#line 667 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.expr) = Expr::makeOpBinary((yyvsp[-2].expr), '%', (yyvsp[0].expr)); }
-#line 3070 "bison_parser.cpp" /* yacc.c:1646  */
+#line 3080 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 110:
-#line 665 "bison_parser.y" /* yacc.c:1646  */
+#line 668 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.expr) = Expr::makeOpBinary((yyvsp[-2].expr), '^', (yyvsp[0].expr)); }
-#line 3076 "bison_parser.cpp" /* yacc.c:1646  */
+#line 3086 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 111:
-#line 666 "bison_parser.y" /* yacc.c:1646  */
-    { (yyval.expr) = Expr::makeOpBinary((yyvsp[-2].expr), Expr::LIKE, (yyvsp[0].expr)); }
-#line 3082 "bison_parser.cpp" /* yacc.c:1646  */
+#line 669 "bison_parser.y" /* yacc.c:1646  */
+    { (yyval.expr) = Expr::makeOpBinary((yyvsp[-2].expr), kOpLike, (yyvsp[0].expr)); }
+#line 3092 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 112:
-#line 667 "bison_parser.y" /* yacc.c:1646  */
-    { (yyval.expr) = Expr::makeOpBinary((yyvsp[-3].expr), Expr::NOT_LIKE, (yyvsp[0].expr)); }
-#line 3088 "bison_parser.cpp" /* yacc.c:1646  */
+#line 670 "bison_parser.y" /* yacc.c:1646  */
+    { (yyval.expr) = Expr::makeOpBinary((yyvsp[-3].expr), kOpNotLike, (yyvsp[0].expr)); }
+#line 3098 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 113:
-#line 671 "bison_parser.y" /* yacc.c:1646  */
-    { (yyval.expr) = Expr::makeOpBinary((yyvsp[-2].expr), Expr::AND, (yyvsp[0].expr)); }
-#line 3094 "bison_parser.cpp" /* yacc.c:1646  */
+#line 674 "bison_parser.y" /* yacc.c:1646  */
+    { (yyval.expr) = Expr::makeOpBinary((yyvsp[-2].expr), kOpAnd, (yyvsp[0].expr)); }
+#line 3104 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 114:
-#line 672 "bison_parser.y" /* yacc.c:1646  */
-    { (yyval.expr) = Expr::makeOpBinary((yyvsp[-2].expr), Expr::OR, (yyvsp[0].expr)); }
-#line 3100 "bison_parser.cpp" /* yacc.c:1646  */
+#line 675 "bison_parser.y" /* yacc.c:1646  */
+    { (yyval.expr) = Expr::makeOpBinary((yyvsp[-2].expr), kOpOr, (yyvsp[0].expr)); }
+#line 3110 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 115:
-#line 676 "bison_parser.y" /* yacc.c:1646  */
+#line 679 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.expr) = Expr::makeInOperator((yyvsp[-4].expr), (yyvsp[-1].expr_vec)); }
-#line 3106 "bison_parser.cpp" /* yacc.c:1646  */
+#line 3116 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 116:
-#line 677 "bison_parser.y" /* yacc.c:1646  */
-    { (yyval.expr) = Expr::makeOpUnary(Expr::NOT, Expr::makeInOperator((yyvsp[-5].expr), (yyvsp[-1].expr_vec))); }
-#line 3112 "bison_parser.cpp" /* yacc.c:1646  */
+#line 680 "bison_parser.y" /* yacc.c:1646  */
+    { (yyval.expr) = Expr::makeOpUnary(kOpNot, Expr::makeInOperator((yyvsp[-5].expr), (yyvsp[-1].expr_vec))); }
+#line 3122 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 117:
-#line 678 "bison_parser.y" /* yacc.c:1646  */
+#line 681 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.expr) = Expr::makeInOperator((yyvsp[-4].expr), (yyvsp[-1].select_stmt)); }
-#line 3118 "bison_parser.cpp" /* yacc.c:1646  */
+#line 3128 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 118:
-#line 679 "bison_parser.y" /* yacc.c:1646  */
-    { (yyval.expr) = Expr::makeOpUnary(Expr::NOT, Expr::makeInOperator((yyvsp[-5].expr), (yyvsp[-1].select_stmt))); }
-#line 3124 "bison_parser.cpp" /* yacc.c:1646  */
+#line 682 "bison_parser.y" /* yacc.c:1646  */
+    { (yyval.expr) = Expr::makeOpUnary(kOpNot, Expr::makeInOperator((yyvsp[-5].expr), (yyvsp[-1].select_stmt))); }
+#line 3134 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 119:
-#line 684 "bison_parser.y" /* yacc.c:1646  */
+#line 687 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.expr) = Expr::makeCase((yyvsp[-5].expr), (yyvsp[-3].expr), (yyvsp[-1].expr)); }
-#line 3130 "bison_parser.cpp" /* yacc.c:1646  */
+#line 3140 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 120:
-#line 688 "bison_parser.y" /* yacc.c:1646  */
+#line 691 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.expr) = Expr::makeExists((yyvsp[-1].select_stmt)); }
-#line 3136 "bison_parser.cpp" /* yacc.c:1646  */
+#line 3146 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 121:
-#line 689 "bison_parser.y" /* yacc.c:1646  */
-    { (yyval.expr) = Expr::makeOpUnary(Expr::NOT, Expr::makeExists((yyvsp[-1].select_stmt))); }
-#line 3142 "bison_parser.cpp" /* yacc.c:1646  */
+#line 692 "bison_parser.y" /* yacc.c:1646  */
+    { (yyval.expr) = Expr::makeOpUnary(kOpNot, Expr::makeExists((yyvsp[-1].select_stmt))); }
+#line 3152 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 122:
-#line 693 "bison_parser.y" /* yacc.c:1646  */
+#line 696 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.expr) = Expr::makeOpBinary((yyvsp[-2].expr), '=', (yyvsp[0].expr)); }
-#line 3148 "bison_parser.cpp" /* yacc.c:1646  */
+#line 3158 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 123:
-#line 694 "bison_parser.y" /* yacc.c:1646  */
-    { (yyval.expr) = Expr::makeOpBinary((yyvsp[-2].expr), Expr::NOT_EQUALS, (yyvsp[0].expr)); }
-#line 3154 "bison_parser.cpp" /* yacc.c:1646  */
+#line 697 "bison_parser.y" /* yacc.c:1646  */
+    { (yyval.expr) = Expr::makeOpBinary((yyvsp[-2].expr), kOpNotEquals, (yyvsp[0].expr)); }
+#line 3164 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 124:
-#line 695 "bison_parser.y" /* yacc.c:1646  */
+#line 698 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.expr) = Expr::makeOpBinary((yyvsp[-2].expr), '<', (yyvsp[0].expr)); }
-#line 3160 "bison_parser.cpp" /* yacc.c:1646  */
+#line 3170 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 125:
-#line 696 "bison_parser.y" /* yacc.c:1646  */
+#line 699 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.expr) = Expr::makeOpBinary((yyvsp[-2].expr), '>', (yyvsp[0].expr)); }
-#line 3166 "bison_parser.cpp" /* yacc.c:1646  */
+#line 3176 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 126:
-#line 697 "bison_parser.y" /* yacc.c:1646  */
-    { (yyval.expr) = Expr::makeOpBinary((yyvsp[-2].expr), Expr::LESS_EQ, (yyvsp[0].expr)); }
-#line 3172 "bison_parser.cpp" /* yacc.c:1646  */
+#line 700 "bison_parser.y" /* yacc.c:1646  */
+    { (yyval.expr) = Expr::makeOpBinary((yyvsp[-2].expr), kOpLessEq, (yyvsp[0].expr)); }
+#line 3182 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 127:
-#line 698 "bison_parser.y" /* yacc.c:1646  */
-    { (yyval.expr) = Expr::makeOpBinary((yyvsp[-2].expr), Expr::GREATER_EQ, (yyvsp[0].expr)); }
-#line 3178 "bison_parser.cpp" /* yacc.c:1646  */
+#line 701 "bison_parser.y" /* yacc.c:1646  */
+    { (yyval.expr) = Expr::makeOpBinary((yyvsp[-2].expr), kOpGreaterEq, (yyvsp[0].expr)); }
+#line 3188 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 128:
-#line 702 "bison_parser.y" /* yacc.c:1646  */
+#line 705 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.expr) = Expr::makeFunctionRef((yyvsp[-4].sval), (yyvsp[-1].expr_vec), (yyvsp[-2].bval)); }
-#line 3184 "bison_parser.cpp" /* yacc.c:1646  */
+#line 3194 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 129:
-#line 706 "bison_parser.y" /* yacc.c:1646  */
+#line 709 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.expr) = Expr::makeBetween((yyvsp[-4].expr), (yyvsp[-2].expr), (yyvsp[0].expr)); }
-#line 3190 "bison_parser.cpp" /* yacc.c:1646  */
+#line 3200 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 130:
-#line 710 "bison_parser.y" /* yacc.c:1646  */
+#line 713 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.expr) = Expr::makeColumnRef((yyvsp[0].sval)); }
-#line 3196 "bison_parser.cpp" /* yacc.c:1646  */
+#line 3206 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 131:
-#line 711 "bison_parser.y" /* yacc.c:1646  */
+#line 714 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.expr) = Expr::makeColumnRef((yyvsp[-2].sval), (yyvsp[0].sval)); }
-#line 3202 "bison_parser.cpp" /* yacc.c:1646  */
+#line 3212 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 135:
-#line 721 "bison_parser.y" /* yacc.c:1646  */
+#line 724 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.expr) = Expr::makeLiteral((yyvsp[0].sval)); }
-#line 3208 "bison_parser.cpp" /* yacc.c:1646  */
+#line 3218 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 136:
-#line 726 "bison_parser.y" /* yacc.c:1646  */
+#line 729 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.expr) = Expr::makeLiteral((yyvsp[0].fval)); }
-#line 3214 "bison_parser.cpp" /* yacc.c:1646  */
+#line 3224 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 138:
-#line 731 "bison_parser.y" /* yacc.c:1646  */
+#line 734 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.expr) = Expr::makeLiteral((yyvsp[0].ival)); }
-#line 3220 "bison_parser.cpp" /* yacc.c:1646  */
+#line 3230 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 139:
-#line 735 "bison_parser.y" /* yacc.c:1646  */
+#line 738 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.expr) = new Expr(kExprStar); }
-#line 3226 "bison_parser.cpp" /* yacc.c:1646  */
+#line 3236 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 140:
-#line 739 "bison_parser.y" /* yacc.c:1646  */
+#line 742 "bison_parser.y" /* yacc.c:1646  */
     {
 			(yyval.expr) = Expr::makePlaceholder(yylloc.total_column);
 			yyloc.placeholder_list.push_back((yyval.expr));
 		}
-#line 3235 "bison_parser.cpp" /* yacc.c:1646  */
+#line 3245 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 142:
-#line 751 "bison_parser.y" /* yacc.c:1646  */
+#line 754 "bison_parser.y" /* yacc.c:1646  */
     {
 			(yyvsp[0].table_vec)->push_back((yyvsp[-2].table));
 			auto tbl = new TableRef(kTableCrossProduct);
 			tbl->list = (yyvsp[0].table_vec);
 			(yyval.table) = tbl;
 		}
-#line 3246 "bison_parser.cpp" /* yacc.c:1646  */
+#line 3256 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 144:
-#line 762 "bison_parser.y" /* yacc.c:1646  */
+#line 765 "bison_parser.y" /* yacc.c:1646  */
     {
 			auto tbl = new TableRef(kTableSelect);
 			tbl->select = (yyvsp[-2].select_stmt);
 			tbl->alias = (yyvsp[0].sval);
 			(yyval.table) = tbl;
 		}
-#line 3257 "bison_parser.cpp" /* yacc.c:1646  */
+#line 3267 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 146:
-#line 773 "bison_parser.y" /* yacc.c:1646  */
+#line 776 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.table_vec) = new std::vector<TableRef*>(); (yyval.table_vec)->push_back((yyvsp[0].table)); }
-#line 3263 "bison_parser.cpp" /* yacc.c:1646  */
+#line 3273 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 147:
-#line 774 "bison_parser.y" /* yacc.c:1646  */
+#line 777 "bison_parser.y" /* yacc.c:1646  */
     { (yyvsp[-2].table_vec)->push_back((yyvsp[0].table)); (yyval.table_vec) = (yyvsp[-2].table_vec); }
-#line 3269 "bison_parser.cpp" /* yacc.c:1646  */
+#line 3279 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 148:
-#line 779 "bison_parser.y" /* yacc.c:1646  */
+#line 782 "bison_parser.y" /* yacc.c:1646  */
     {
 			auto tbl = new TableRef(kTableName);
 			tbl->name = (yyvsp[-1].sval);
 			tbl->alias = (yyvsp[0].sval);
 			(yyval.table) = tbl;
 		}
-#line 3280 "bison_parser.cpp" /* yacc.c:1646  */
+#line 3290 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 149:
-#line 789 "bison_parser.y" /* yacc.c:1646  */
+#line 792 "bison_parser.y" /* yacc.c:1646  */
     {
 			(yyval.table) = new TableRef(kTableName);
 			(yyval.table)->name = (yyvsp[0].sval);
 		}
-#line 3289 "bison_parser.cpp" /* yacc.c:1646  */
+#line 3299 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 152:
-#line 803 "bison_parser.y" /* yacc.c:1646  */
+#line 806 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.sval) = (yyvsp[0].sval); }
-#line 3295 "bison_parser.cpp" /* yacc.c:1646  */
+#line 3305 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 155:
-#line 809 "bison_parser.y" /* yacc.c:1646  */
+#line 812 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.sval) = NULL; }
-#line 3301 "bison_parser.cpp" /* yacc.c:1646  */
+#line 3311 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 156:
-#line 818 "bison_parser.y" /* yacc.c:1646  */
+#line 821 "bison_parser.y" /* yacc.c:1646  */
     { 
 			(yyval.table) = new TableRef(kTableJoin);
 			(yyval.table)->join = new JoinDefinition();
@@ -3310,88 +3320,88 @@ yyreduce:
 			(yyval.table)->join->right = (yyvsp[-2].table);
 			(yyval.table)->join->condition = (yyvsp[0].expr);
 		}
-#line 3314 "bison_parser.cpp" /* yacc.c:1646  */
+#line 3324 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 157:
-#line 829 "bison_parser.y" /* yacc.c:1646  */
+#line 832 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.uval) = kJoinInner; }
-#line 3320 "bison_parser.cpp" /* yacc.c:1646  */
+#line 3330 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 158:
-#line 830 "bison_parser.y" /* yacc.c:1646  */
+#line 833 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.uval) = kJoinOuter; }
-#line 3326 "bison_parser.cpp" /* yacc.c:1646  */
+#line 3336 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 159:
-#line 831 "bison_parser.y" /* yacc.c:1646  */
+#line 834 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.uval) = kJoinLeftOuter; }
-#line 3332 "bison_parser.cpp" /* yacc.c:1646  */
+#line 3342 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 160:
-#line 832 "bison_parser.y" /* yacc.c:1646  */
+#line 835 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.uval) = kJoinRightOuter; }
-#line 3338 "bison_parser.cpp" /* yacc.c:1646  */
+#line 3348 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 161:
-#line 833 "bison_parser.y" /* yacc.c:1646  */
+#line 836 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.uval) = kJoinLeft; }
-#line 3344 "bison_parser.cpp" /* yacc.c:1646  */
+#line 3354 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 162:
-#line 834 "bison_parser.y" /* yacc.c:1646  */
+#line 837 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.uval) = kJoinRight; }
-#line 3350 "bison_parser.cpp" /* yacc.c:1646  */
+#line 3360 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 163:
-#line 835 "bison_parser.y" /* yacc.c:1646  */
+#line 838 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.uval) = kJoinCross; }
-#line 3356 "bison_parser.cpp" /* yacc.c:1646  */
+#line 3366 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 164:
-#line 836 "bison_parser.y" /* yacc.c:1646  */
+#line 839 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.uval) = kJoinNatural; }
-#line 3362 "bison_parser.cpp" /* yacc.c:1646  */
+#line 3372 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 165:
-#line 837 "bison_parser.y" /* yacc.c:1646  */
+#line 840 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.uval) = kJoinInner; }
-#line 3368 "bison_parser.cpp" /* yacc.c:1646  */
+#line 3378 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 166:
-#line 843 "bison_parser.y" /* yacc.c:1646  */
+#line 846 "bison_parser.y" /* yacc.c:1646  */
     {
 			auto tbl = new TableRef(kTableSelect);
 			tbl->select = (yyvsp[-2].select_stmt);
 			tbl->alias = (yyvsp[0].sval);
 			(yyval.table) = tbl;
 		}
-#line 3379 "bison_parser.cpp" /* yacc.c:1646  */
+#line 3389 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 171:
-#line 868 "bison_parser.y" /* yacc.c:1646  */
+#line 871 "bison_parser.y" /* yacc.c:1646  */
     { (yyval.str_vec) = new std::vector<char*>(); (yyval.str_vec)->push_back((yyvsp[0].sval)); }
-#line 3385 "bison_parser.cpp" /* yacc.c:1646  */
+#line 3395 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
   case 172:
-#line 869 "bison_parser.y" /* yacc.c:1646  */
+#line 872 "bison_parser.y" /* yacc.c:1646  */
     { (yyvsp[-2].str_vec)->push_back((yyvsp[0].sval)); (yyval.str_vec) = (yyvsp[-2].str_vec); }
-#line 3391 "bison_parser.cpp" /* yacc.c:1646  */
+#line 3401 "bison_parser.cpp" /* yacc.c:1646  */
     break;
 
 
-#line 3395 "bison_parser.cpp" /* yacc.c:1646  */
+#line 3405 "bison_parser.cpp" /* yacc.c:1646  */
       default: break;
     }
   /* User semantic actions sometimes alter yychar, and that requires
@@ -3626,7 +3636,7 @@ yyreturn:
 #endif
   return yyresult;
 }
-#line 872 "bison_parser.y" /* yacc.c:1906  */
+#line 875 "bison_parser.y" /* yacc.c:1906  */
 
 /*********************************
  ** Section 4: Additional C code
diff --git a/src/parser/bison_parser.h b/src/parser/bison_parser.h
index 2790efe..fecc6aa 100644
--- a/src/parser/bison_parser.h
+++ b/src/parser/bison_parser.h
@@ -48,7 +48,7 @@
 extern int hsql_debug;
 #endif
 /* "%code requires" blocks.  */
-#line 41 "bison_parser.y" /* yacc.c:1909  */
+#line 36 "bison_parser.y" /* yacc.c:1909  */
 
 // %code requires block	
 
@@ -214,7 +214,7 @@ extern int hsql_debug;
 
 union HSQL_STYPE
 {
-#line 100 "bison_parser.y" /* yacc.c:1909  */
+#line 95 "bison_parser.y" /* yacc.c:1909  */
 
 	double fval;
 	int64_t ival;
@@ -242,7 +242,7 @@ union HSQL_STYPE
 	hsql::GroupByDescription* group_t;
 	hsql::UpdateClause* update_t;
 
-	hsql::SQLParserResult* stmt_list;
+	std::vector<hsql::SQLStatement*>* stmt_vec;
 
 	std::vector<char*>* str_vec;
 	std::vector<hsql::TableRef*>* table_vec;
@@ -275,6 +275,6 @@ struct HSQL_LTYPE
 
 
 
-int hsql_parse (hsql::SQLParserResult** result, yyscan_t scanner);
+int hsql_parse (hsql::SQLParserResult* result, yyscan_t scanner);
 
 #endif /* !YY_HSQL_BISON_PARSER_H_INCLUDED  */
diff --git a/src/parser/bison_parser.y b/src/parser/bison_parser.y
index 7593212..c0252d0 100644
--- a/src/parser/bison_parser.y
+++ b/src/parser/bison_parser.y
@@ -18,14 +18,9 @@
 
 using namespace hsql;
 
-int yyerror(YYLTYPE* llocp, SQLParserResult** result, yyscan_t scanner, const char *msg) {
-	delete *result;
-
-	SQLParserResult* list = new SQLParserResult();
-	list->setIsValid(false);
-	list->setErrorDetails(strdup(msg), llocp->first_line, llocp->first_column);
-
-	*result = list;
+int yyerror(YYLTYPE* llocp, SQLParserResult* result, yyscan_t scanner, const char *msg) {
+	result->setIsValid(false);
+	result->setErrorDetails(strdup(msg), llocp->first_line, llocp->first_column);
 	return 0;
 }
 
@@ -90,7 +85,7 @@ int yyerror(YYLTYPE* llocp, SQLParserResult** result, yyscan_t scanner, const ch
 %lex-param   { yyscan_t scanner }
 
 // Define additional parameters for yyparse
-%parse-param { hsql::SQLParserResult** result }
+%parse-param { hsql::SQLParserResult* result }
 %parse-param { yyscan_t scanner }
 
 
@@ -124,7 +119,7 @@ int yyerror(YYLTYPE* llocp, SQLParserResult** result, yyscan_t scanner, const ch
 	hsql::GroupByDescription* group_t;
 	hsql::UpdateClause* update_t;
 
-	hsql::SQLParserResult* stmt_list;
+	std::vector<hsql::SQLStatement*>* stmt_vec;
 
 	std::vector<char*>* str_vec;
 	std::vector<hsql::TableRef*>* table_vec;
@@ -147,7 +142,7 @@ int yyerror(YYLTYPE* llocp, SQLParserResult** result, yyscan_t scanner, const ch
 		}
 	}
 	delete ($$);
-} <str_vec> <table_vec> <column_vec> <update_vec> <expr_vec> <order_vec>
+} <str_vec> <table_vec> <column_vec> <update_vec> <expr_vec> <order_vec> <stmt_vec>
 %destructor { delete ($$); } <*>
 
 
@@ -178,7 +173,7 @@ int yyerror(YYLTYPE* llocp, SQLParserResult** result, yyscan_t scanner, const ch
 /*********************************
  ** Non-Terminal types (http://www.gnu.org/software/bison/manual/html_node/Type-Decl.html)
  *********************************/
-%type <stmt_list>	statement_list
+%type <stmt_vec>	statement_list
 %type <statement> 	statement preparable_statement
 %type <exec_stmt>	execute_statement
 %type <prep_stmt>	prepare_statement
@@ -243,14 +238,18 @@ int yyerror(YYLTYPE* llocp, SQLParserResult** result, yyscan_t scanner, const ch
 // Defines our general input.
 input:
 		statement_list opt_semicolon {
-			*result = $1;
+		  for (SQLStatement* stmt : *$1) {
+		    // Transfers ownership of the statement.
+		  	result->addStatement(stmt);
+		  }
+		  delete $1;
 		}
 	;
 
 
 statement_list:
-		statement { $$ = new SQLParserResult($1); }
-	|	statement_list ';' statement { $1->addStatement($3); $$ = $1; }
+		statement { $$ = new std::vector<SQLStatement*>(); $$->push_back($1); }
+	|	statement_list ';' statement { $1->push_back($3); $$ = $1; }
 	;
 
 statement:
@@ -288,7 +287,11 @@ prepare_statement:
 	|	PREPARE IDENTIFIER '{' statement_list opt_semicolon '}' {
 			$$ = new PrepareStatement();
 			$$->name = $2;
-			$$->query = $4;
+			$$->query = new SQLParserResult();
+		  for (SQLStatement* stmt : *$4) {
+		  	$$->query->addStatement(stmt);
+		  }
+		  delete $4;
 		}
 	;
 
@@ -651,8 +654,8 @@ scalar_expr:
 	;
 
 unary_expr:
-		'-' operand { $$ = Expr::makeOpUnary(Expr::UMINUS, $2); }
-	|	NOT operand { $$ = Expr::makeOpUnary(Expr::NOT, $2); }
+		'-' operand { $$ = Expr::makeOpUnary(kOpMinus, $2); }
+	|	NOT operand { $$ = Expr::makeOpUnary(kOpNot, $2); }
 	;
 
 binary_expr:
@@ -663,20 +666,20 @@ binary_expr:
 	|	operand '*' operand			{ $$ = Expr::makeOpBinary($1, '*', $3); }
 	|	operand '%' operand			{ $$ = Expr::makeOpBinary($1, '%', $3); }
 	|	operand '^' operand			{ $$ = Expr::makeOpBinary($1, '^', $3); }
-	|	operand LIKE operand		{ $$ = Expr::makeOpBinary($1, Expr::LIKE, $3); }
-	|	operand NOT LIKE operand	{ $$ = Expr::makeOpBinary($1, Expr::NOT_LIKE, $4); }
+	|	operand LIKE operand		{ $$ = Expr::makeOpBinary($1, kOpLike, $3); }
+	|	operand NOT LIKE operand	{ $$ = Expr::makeOpBinary($1, kOpNotLike, $4); }
 	;
 
 logic_expr:
-		expr AND expr	{ $$ = Expr::makeOpBinary($1, Expr::AND, $3); }
-	|	expr OR expr	{ $$ = Expr::makeOpBinary($1, Expr::OR, $3); }
+		expr AND expr	{ $$ = Expr::makeOpBinary($1, kOpAnd, $3); }
+	|	expr OR expr	{ $$ = Expr::makeOpBinary($1, kOpOr, $3); }
 	;
 
 in_expr:
 		operand IN '(' expr_list ')'			{ $$ = Expr::makeInOperator($1, $4); }
-	|	operand NOT IN '(' expr_list ')'		{ $$ = Expr::makeOpUnary(Expr::NOT, Expr::makeInOperator($1, $5)); }
+	|	operand NOT IN '(' expr_list ')'		{ $$ = Expr::makeOpUnary(kOpNot, Expr::makeInOperator($1, $5)); }
 	|	operand IN '(' select_no_paren ')'		{ $$ = Expr::makeInOperator($1, $4); }
-	|	operand NOT IN '(' select_no_paren ')'	{ $$ = Expr::makeOpUnary(Expr::NOT, Expr::makeInOperator($1, $5)); }
+	|	operand NOT IN '(' select_no_paren ')'	{ $$ = Expr::makeOpUnary(kOpNot, Expr::makeInOperator($1, $5)); }
 	;
 
 // TODO: allow no else specified
@@ -686,16 +689,16 @@ case_expr:
 
 exists_expr:
 		EXISTS '(' select_no_paren ')' { $$ = Expr::makeExists($3); }
-	|	NOT EXISTS '(' select_no_paren ')' { $$ = Expr::makeOpUnary(Expr::NOT, Expr::makeExists($4)); }
+	|	NOT EXISTS '(' select_no_paren ')' { $$ = Expr::makeOpUnary(kOpNot, Expr::makeExists($4)); }
 	;
 
 comp_expr:
 		operand '=' operand			{ $$ = Expr::makeOpBinary($1, '=', $3); }
-	|	operand NOTEQUALS operand	{ $$ = Expr::makeOpBinary($1, Expr::NOT_EQUALS, $3); }
+	|	operand NOTEQUALS operand	{ $$ = Expr::makeOpBinary($1, kOpNotEquals, $3); }
 	|	operand '<' operand			{ $$ = Expr::makeOpBinary($1, '<', $3); }
 	|	operand '>' operand			{ $$ = Expr::makeOpBinary($1, '>', $3); }
-	|	operand LESSEQ operand		{ $$ = Expr::makeOpBinary($1, Expr::LESS_EQ, $3); }
-	|	operand GREATEREQ operand	{ $$ = Expr::makeOpBinary($1, Expr::GREATER_EQ, $3); }
+	|	operand LESSEQ operand		{ $$ = Expr::makeOpBinary($1, kOpLessEq, $3); }
+	|	operand GREATEREQ operand	{ $$ = Expr::makeOpBinary($1, kOpGreaterEq, $3); }
 	;
 
 function_expr:
diff --git a/src/sql/CreateStatement.h b/src/sql/CreateStatement.h
index 5b96d33..92e4d39 100644
--- a/src/sql/CreateStatement.h
+++ b/src/sql/CreateStatement.h
@@ -1,5 +1,5 @@
-#ifndef __CREATE_STATEMENT_H__
-#define __CREATE_STATEMENT_H__
+#ifndef __SQLPARSER__CREATE_STATEMENT_H__
+#define __SQLPARSER__CREATE_STATEMENT_H__
 
 #include "SQLStatement.h"
 
diff --git a/src/sql/DeleteStatement.h b/src/sql/DeleteStatement.h
index ed4d77d..af34352 100644
--- a/src/sql/DeleteStatement.h
+++ b/src/sql/DeleteStatement.h
@@ -1,5 +1,5 @@
-#ifndef __DELETE_STATEMENT_H__
-#define __DELETE_STATEMENT_H__
+#ifndef __SQLPARSER__DELETE_STATEMENT_H__
+#define __SQLPARSER__DELETE_STATEMENT_H__
 
 #include "SQLStatement.h"
 
diff --git a/src/sql/DropStatement.h b/src/sql/DropStatement.h
index 08c1b53..18b1363 100644
--- a/src/sql/DropStatement.h
+++ b/src/sql/DropStatement.h
@@ -1,5 +1,5 @@
-#ifndef __DROP_STATEMENT_H__
-#define __DROP_STATEMENT_H__
+#ifndef __SQLPARSER__DROP_STATEMENT_H__
+#define __SQLPARSER__DROP_STATEMENT_H__
 
 #include "SQLStatement.h"
 
diff --git a/src/sql/ExecuteStatement.h b/src/sql/ExecuteStatement.h
index 2f5db10..0bd9c42 100644
--- a/src/sql/ExecuteStatement.h
+++ b/src/sql/ExecuteStatement.h
@@ -1,5 +1,5 @@
-#ifndef __EXECUTE_STATEMENT_H__
-#define __EXECUTE_STATEMENT_H__
+#ifndef __SQLPARSER__EXECUTE_STATEMENT_H__
+#define __SQLPARSER__EXECUTE_STATEMENT_H__
 
 #include "SQLStatement.h"
 
diff --git a/src/sql/Expr.cpp b/src/sql/Expr.cpp
index f1ebe9b..1345714 100644
--- a/src/sql/Expr.cpp
+++ b/src/sql/Expr.cpp
@@ -51,7 +51,7 @@ namespace hsql {
 
   Expr* Expr::makeOpBinary(Expr* expr1, char op, Expr* expr2) {
     Expr* e = new Expr(kExprOperator);
-    e->opType = SIMPLE_OP;
+    e->opType = kOpSimple;
     e->opChar = op;
     e->expr = expr1;
     e->expr2 = expr2;
@@ -61,7 +61,7 @@ namespace hsql {
   Expr* Expr::makeBetween(Expr* expr, Expr* left, Expr* right) {
     Expr* e = new Expr(kExprOperator);
     e->expr = expr;
-    e->opType = BETWEEN;
+    e->opType = kOpBetween;
     e->exprList = new std::vector<Expr*>();
     e->exprList->push_back(left);
     e->exprList->push_back(right);
@@ -71,7 +71,7 @@ namespace hsql {
   Expr* Expr::makeCase(Expr* expr, Expr* then, Expr* other) {
     Expr* e = new Expr(kExprOperator);
     e->expr = expr;
-    e->opType = CASE;
+    e->opType = kOpCase;
     e->exprList = new std::vector<Expr*>();
     e->exprList->push_back(then);
     e->exprList->push_back(other);
@@ -132,14 +132,14 @@ namespace hsql {
 
   Expr* Expr::makeExists(SelectStatement* select) {
     Expr* e = new Expr(kExprOperator);
-    e->opType = EXISTS;
+    e->opType = kOpExists;
     e->select = select;
     return e;
   }
 
   Expr* Expr::makeInOperator(Expr* expr, std::vector<Expr*>* exprList) {
     Expr* e = new Expr(kExprOperator);
-    e->opType = IN;
+    e->opType = kOpIn;
     e->expr = expr;
     e->exprList = exprList;
 
@@ -148,39 +148,39 @@ namespace hsql {
 
   Expr* Expr::makeInOperator(Expr* expr, SelectStatement* select) {
     Expr* e = new Expr(kExprOperator);
-    e->opType = IN;
+    e->opType = kOpIn;
     e->expr = expr;
     e->select = select;
 
     return e;
   }
 
-  bool Expr::isType(ExprType e_type) {
-    return e_type == type;
+  bool Expr::isType(ExprType exprType) const {
+    return exprType == type;
   }
 
-  bool Expr::isLiteral() {
+  bool Expr::isLiteral() const {
     return isType(kExprLiteralInt) || isType(kExprLiteralFloat) || isType(kExprLiteralString) || isType(kExprPlaceholder);
   }
 
-  bool Expr::hasAlias() {
+  bool Expr::hasAlias() const {
     return alias != NULL;
   }
 
-  bool Expr::hasTable() {
+  bool Expr::hasTable() const {
     return table != NULL;
   }
 
-  char* Expr::getName() {
+  const char* Expr::getName() const {
     if (alias != NULL) return alias;
     else return name;
   }
 
-  bool Expr::isSimpleOp() {
-    return opType == SIMPLE_OP;
+  bool Expr::isSimpleOp() const {
+    return opType == kOpSimple;
   }
 
-  bool Expr::isSimpleOp(char op) {
+  bool Expr::isSimpleOp(char op) const {
     return isSimpleOp() && opChar == op;
   }
 
diff --git a/src/sql/Expr.h b/src/sql/Expr.h
index 3284802..bba37bd 100644
--- a/src/sql/Expr.h
+++ b/src/sql/Expr.h
@@ -1,5 +1,5 @@
-#ifndef __EXPRESSION_H__
-#define __EXPRESSION_H__
+#ifndef __SQLPARSER__EXPR_H__
+#define __SQLPARSER__EXPR_H__
 
 #include <stdlib.h>
 #include <memory>
@@ -24,48 +24,45 @@ namespace hsql {
     kExprSelect
   };
 
+  // Operator types. These are important for expressions of type kExprOperator.
+  // Trivial types are those that can be described by a single character e.g:
+  // + - * / < > = %
+  // Non-trivial are: <> <= >= LIKE ISNULL NOT
+  enum OperatorType {
+    kOpNone,
+
+    // Ternary operators
+    kOpBetween,
+    kOpCase,
+
+    // Binary operators.
+    // Simple operators are identified by the opChar field (e.g. +, -, =, >, <).
+    kOpSimple,
+
+    kOpNotEquals,
+    kOpLessEq,
+    kOpGreaterEq,
+    kOpLike,
+    kOpNotLike,
+    kOpAnd,
+    kOpOr,
+    kOpIn,
+
+    // Unary operators.
+    kOpNot,
+    kOpMinus,
+    kOpIsNull,
+    kOpExists
+  };
+
   typedef struct Expr Expr;
 
   // Represents SQL expressions (i.e. literals, operators, column_refs).
   // TODO: When destructing a placeholder expression, we might need to alter the placeholder_list.
   struct Expr {
-    // Operator types. These are important for expressions of type kExprOperator.
-    // Trivial types are those that can be described by a single character e.g:
-    // + - * / < > = %
-    // Non-trivial are: <> <= >= LIKE ISNULL NOT
-    enum OperatorType {
-      NONE,
-
-      // Ternary operators
-      BETWEEN,
-      CASE,
-
-      // Binary operators.
-      SIMPLE_OP,
-      NOT_EQUALS,
-      LESS_EQ,
-      GREATER_EQ,
-      LIKE,
-      NOT_LIKE,
-      AND,
-      OR,
-      IN,
-
-      // Unary operators.
-      NOT,
-      UMINUS,
-      ISNULL,
-      EXISTS
-    };
-
-
 
     Expr(ExprType type);
-
-    // Interesting side-effect:
-    // Making the destructor virtual used to cause segmentation faults.
-    // TODO: inspect.
-    ~Expr();
+    virtual ~Expr();
 
     ExprType type;
 
@@ -88,19 +85,19 @@ namespace hsql {
 
     // Convenience accessor methods.
 
-    bool isType(ExprType e_type);
+    bool isType(ExprType exprType) const;
 
-    bool isLiteral();
+    bool isLiteral() const;
 
-    bool hasAlias();
+    bool hasAlias() const;
 
-    bool hasTable();
+    bool hasTable() const;
 
-    char* getName();
+    const char* getName() const;
 
-    bool isSimpleOp();
+    bool isSimpleOp() const;
 
-    bool isSimpleOp(char op);
+    bool isSimpleOp(char op) const;
 
 
     // Static constructors.
diff --git a/src/sql/ImportStatement.h b/src/sql/ImportStatement.h
index 4fb3e3e..1290713 100644
--- a/src/sql/ImportStatement.h
+++ b/src/sql/ImportStatement.h
@@ -1,5 +1,5 @@
-#ifndef __IMPORT_STATEMENT_H__
-#define __IMPORT_STATEMENT_H__
+#ifndef __SQLPARSER__IMPORT_STATEMENT_H__
+#define __SQLPARSER__IMPORT_STATEMENT_H__
 
 #include "SQLStatement.h"
 
diff --git a/src/sql/InsertStatement.h b/src/sql/InsertStatement.h
index 06184fa..3aa8fd2 100644
--- a/src/sql/InsertStatement.h
+++ b/src/sql/InsertStatement.h
@@ -1,5 +1,5 @@
-#ifndef __INSERT_STATEMENT_H__
-#define __INSERT_STATEMENT_H__
+#ifndef __SQLPARSER__INSERT_STATEMENT_H__
+#define __SQLPARSER__INSERT_STATEMENT_H__
 
 #include "SQLStatement.h"
 #include "SelectStatement.h"
diff --git a/src/sql/PrepareStatement.h b/src/sql/PrepareStatement.h
index 9455952..62891eb 100644
--- a/src/sql/PrepareStatement.h
+++ b/src/sql/PrepareStatement.h
@@ -1,5 +1,5 @@
-#ifndef __PREPARE_STATEMENT_H__
-#define __PREPARE_STATEMENT_H__
+#ifndef __SQLPARSER__PREPARE_STATEMENT_H__
+#define __SQLPARSER__PREPARE_STATEMENT_H__
 
 #include "../SQLParserResult.h"
 #include "SQLStatement.h"
@@ -24,6 +24,8 @@ namespace hsql {
     void setPlaceholders(std::vector<void*> ph);
 
     char* name;
+
+    // The result that is stored within this prepared statement.
     SQLParserResult* query;
 
     // The expressions are not owned by this statement.
diff --git a/src/sql/SQLStatement.h b/src/sql/SQLStatement.h
index 4c87cb8..9d491d4 100644
--- a/src/sql/SQLStatement.h
+++ b/src/sql/SQLStatement.h
@@ -1,5 +1,5 @@
-#ifndef __SQLSTATEMENT_H__
-#define __SQLSTATEMENT_H__
+#ifndef __SQLPARSER__SQLSTATEMENT_H__
+#define __SQLPARSER__SQLSTATEMENT_H__
 
 #include "Expr.h"
 #include <vector>
@@ -29,11 +29,13 @@ namespace hsql {
 
     virtual ~SQLStatement();
 
-    virtual StatementType type() const;
+    StatementType type() const;
+
+    bool isType(StatementType type) const;
 
    private:
     StatementType type_;
   };
 
 } // namespace hsql
-#endif // __SQLSTATEMENT_H__
+#endif // __SQLPARSER__SQLSTATEMENT_H__
diff --git a/src/sql/SelectStatement.h b/src/sql/SelectStatement.h
index bb60836..095310e 100644
--- a/src/sql/SelectStatement.h
+++ b/src/sql/SelectStatement.h
@@ -1,5 +1,5 @@
-#ifndef __SELECT_STATEMENT_H__
-#define __SELECT_STATEMENT_H__
+#ifndef __SQLPARSER__SELECT_STATEMENT_H__
+#define __SQLPARSER__SELECT_STATEMENT_H__
 
 #include "SQLStatement.h"
 #include "Expr.h"
@@ -13,7 +13,6 @@ namespace hsql {
 
   /**
    * Description of the order by clause within a select statement
-   * TODO: hold multiple expressions to be sorted by
    */
   struct OrderDescription {
     OrderDescription(OrderType type, Expr* expr);
@@ -41,8 +40,7 @@ namespace hsql {
    */
   struct GroupByDescription {
     GroupByDescription();
-    // TODO: make virtual
-    ~GroupByDescription();
+    virtual ~GroupByDescription();
 
     std::vector<Expr*>* columns;
     Expr* having;
diff --git a/src/sql/Table.h b/src/sql/Table.h
index 58ecca4..96ee775 100644
--- a/src/sql/Table.h
+++ b/src/sql/Table.h
@@ -1,5 +1,5 @@
-#ifndef __TABLEREF_H__
-#define __TABLEREF_H__
+#ifndef __SQLPARSER__TABLEREF_H__
+#define __SQLPARSER__TABLEREF_H__
 
 #include "Expr.h"
 #include <stdio.h>
@@ -35,10 +35,10 @@ namespace hsql {
     JoinDefinition* join;
 
     // Returns true if a schema is set.
-    bool hasSchema();
+    bool hasSchema() const;
 
     // Returns the alias, if it is set. Otherwise the name.
-    char* getName();
+    const char* getName() const;
   };
 
   // Possible types of joins.
diff --git a/src/sql/UpdateStatement.h b/src/sql/UpdateStatement.h
index b4d6e28..744d55b 100644
--- a/src/sql/UpdateStatement.h
+++ b/src/sql/UpdateStatement.h
@@ -1,5 +1,5 @@
-#ifndef __UPDATE_STATEMENT_H__
-#define __UPDATE_STATEMENT_H__
+#ifndef __SQLPARSER__UPDATE_STATEMENT_H__
+#define __SQLPARSER__UPDATE_STATEMENT_H__
 
 #include "SQLStatement.h"
 
diff --git a/src/sql/statements.cpp b/src/sql/statements.cpp
index 69ffc84..bcdece3 100644
--- a/src/sql/statements.cpp
+++ b/src/sql/statements.cpp
@@ -13,6 +13,10 @@ namespace hsql {
     return type_;
   }
 
+  bool SQLStatement::isType(StatementType type) const {
+    return (type_ == type);
+  }
+
   // ColumnDefinition
   ColumnDefinition::ColumnDefinition(char* name, DataType type) :
     name(name),
@@ -268,11 +272,11 @@ namespace hsql {
     }
   }
 
-  bool TableRef::hasSchema() {
+  bool TableRef::hasSchema() const {
     return schema != NULL;
   }
 
-  char* TableRef::getName() {
+  const char* TableRef::getName() const {
     if (alias != NULL) return alias;
     else return name;
   }
diff --git a/src/sql/statements.h b/src/sql/statements.h
index 13c4a30..d9e59ea 100644
--- a/src/sql/statements.h
+++ b/src/sql/statements.h
@@ -1,5 +1,5 @@
-#ifndef __STATEMENTS_H__
-#define __STATEMENTS_H__
+#ifndef __SQLPARSER__STATEMENTS_H__
+#define __SQLPARSER__STATEMENTS_H__
 
 #include "SelectStatement.h"
 #include "ImportStatement.h"
@@ -11,4 +11,4 @@
 #include "PrepareStatement.h"
 #include "ExecuteStatement.h"
 
-#endif // __STATEMENTS_H__ 
\ No newline at end of file
+#endif // __SQLPARSER__STATEMENTS_H__ 
\ No newline at end of file
diff --git a/src/sqlhelper.cpp b/src/util/sqlhelper.cpp
similarity index 98%
rename from src/sqlhelper.cpp
rename to src/util/sqlhelper.cpp
index 529cead..36aefc8 100644
--- a/src/sqlhelper.cpp
+++ b/src/util/sqlhelper.cpp
@@ -63,16 +63,16 @@ namespace hsql {
     }
 
     switch (expr->opType) {
-    case Expr::SIMPLE_OP:
+    case kOpSimple:
       inprintC(expr->opChar, numIndent);
       break;
-    case Expr::AND:
+    case kOpAnd:
       inprint("AND", numIndent);
       break;
-    case Expr::OR:
+    case kOpOr:
       inprint("OR", numIndent);
       break;
-    case Expr::NOT:
+    case kOpNot:
       inprint("NOT", numIndent);
       break;
     default:
diff --git a/src/sqlhelper.h b/src/util/sqlhelper.h
similarity index 90%
rename from src/sqlhelper.h
rename to src/util/sqlhelper.h
index ea6edd1..7c7e811 100644
--- a/src/sqlhelper.h
+++ b/src/util/sqlhelper.h
@@ -1,7 +1,7 @@
-#ifndef __SQLHELPER_H__
-#define __SQLHELPER_H__
+#ifndef __SQLPARSER__SQLHELPER_H__
+#define __SQLPARSER__SQLHELPER_H__
 
-#include "sql/statements.h"
+#include "../sql/statements.h"
 
 namespace hsql {
 
diff --git a/test/prepare_tests.cpp b/test/prepare_tests.cpp
new file mode 100644
index 0000000..bd8c51d
--- /dev/null
+++ b/test/prepare_tests.cpp
@@ -0,0 +1,82 @@
+
+#include "thirdparty/microtest/microtest.h"
+#include "sql_asserts.h"
+#include "SQLParser.h"
+
+using hsql::kExprPlaceholder;
+
+using hsql::kStmtDrop;
+using hsql::kStmtExecute;
+using hsql::kStmtInsert;
+using hsql::kStmtPrepare;
+using hsql::kStmtSelect;
+
+using hsql::DropStatement;
+using hsql::ExecuteStatement;
+using hsql::InsertStatement;
+using hsql::PrepareStatement;
+using hsql::SelectStatement;
+
+
+TEST(PrepareSingleStatementTest) {
+  const std::string query = "PREPARE test: SELECT * FROM students WHERE grade = ?;";
+  TEST_PARSE_SINGLE_SQL(query, kStmtPrepare, PrepareStatement, result, prepare);
+
+  const SelectStatement* select = (const SelectStatement*) prepare->query->getStatement(0);
+
+  ASSERT(select->whereClause->isSimpleOp('='));
+  ASSERT_EQ(select->whereClause->expr2, prepare->placeholders[0])
+}
+
+TEST(PrepareMultiStatementTest) {
+  const std::string query = "PREPARE test {"
+                            "INSERT INTO test VALUES(?);"
+                            "SELECT ?, test FROM test WHERE c1 = ?;"
+                            "};"
+                            "PREPARE stmt: SELECT * FROM data WHERE c1 = ?;"
+                            "DEALLOCATE PREPARE stmt;";
+
+  TEST_PARSE_SQL_QUERY(query, result, 3);
+
+  TEST_CAST_STMT(result, 0, kStmtPrepare, PrepareStatement, prep1);
+  TEST_CAST_STMT(result, 1, kStmtPrepare, PrepareStatement, prep2);
+  TEST_CAST_STMT(result, 2, kStmtDrop, DropStatement, drop);
+
+  // Prepare Statement #1
+  ASSERT_STREQ(prep1->name, "test");
+  ASSERT_EQ(prep1->placeholders.size(), 3);
+  ASSERT_EQ(prep1->query->size(), 2);
+
+  TEST_CAST_STMT((*prep1->query), 0, kStmtInsert, InsertStatement, insert);
+  TEST_CAST_STMT((*prep1->query), 1, kStmtSelect, SelectStatement, select);
+
+  ASSERT(insert->values->at(0)->isType(kExprPlaceholder));
+  ASSERT(select->selectList->at(0)->isType(kExprPlaceholder));
+  ASSERT(select->whereClause->expr2->isType(kExprPlaceholder));
+
+  // Check IDs of placeholders
+  ASSERT_EQ(insert->values->at(0)->ival, 0);
+  ASSERT_EQ(insert->values->at(0), prep1->placeholders[0]);
+
+  ASSERT_EQ(select->selectList->at(0)->ival, 1);
+  ASSERT_EQ(select->selectList->at(0), prep1->placeholders[1]);
+
+  ASSERT_EQ(select->whereClause->expr2->ival, 2);
+  ASSERT_EQ(select->whereClause->expr2, prep1->placeholders[2]);
+
+  // Prepare Statement #2
+  ASSERT_STREQ(prep2->name, "stmt");
+  ASSERT_EQ(prep2->placeholders.size(), 1);
+
+  // Deallocate Statement
+  ASSERT_EQ(drop->type, DropStatement::kPreparedStatement);
+  ASSERT_STREQ(drop->name, "stmt");
+}
+
+
+TEST(ExecuteStatementTest) {
+  TEST_PARSE_SINGLE_SQL("EXECUTE test(1, 2);", kStmtExecute, ExecuteStatement, result, stmt);
+
+  ASSERT_STREQ(stmt->name, "test");
+  ASSERT_EQ(stmt->parameters->size(), 2);
+}
diff --git a/test/select_tests.cpp b/test/select_tests.cpp
index 7a0ddd3..0256cf2 100644
--- a/test/select_tests.cpp
+++ b/test/select_tests.cpp
@@ -16,8 +16,6 @@ TEST(SelectTest) {
 
   ASSERT_NULL(stmt->whereClause);
   ASSERT_NULL(stmt->groupBy);
-
-  delete result;
 }
 
 TEST(SelectExprTest) {
@@ -55,8 +53,6 @@ TEST(SelectExprTest) {
   ASSERT_EQ(stmt->selectList->at(2)->exprList->at(1)->exprList->size(), 1);
   ASSERT(stmt->selectList->at(2)->exprList->at(1)->exprList->at(0)->isType(kExprColumnRef));
   ASSERT_STREQ(stmt->selectList->at(2)->exprList->at(1)->exprList->at(0)->getName(), "un");
-
-  delete result;
 }
 
 
@@ -76,8 +72,6 @@ TEST(SelectHavingTest) {
   ASSERT(group->having->isSimpleOp('<'));
   ASSERT(group->having->expr->isType(kExprFunctionRef));
   ASSERT(group->having->expr2->isType(kExprLiteralFloat));
-
-  delete result;
 }
 
 
@@ -91,8 +85,6 @@ TEST(SelectDistinctTest) {
 
   ASSERT(stmt->selectDistinct);
   ASSERT_NULL(stmt->whereClause);
-
-  delete result;
 }
 
 TEST(SelectGroupDistinctTest) {
@@ -107,8 +99,6 @@ TEST(SelectGroupDistinctTest) {
   ASSERT_EQ(stmt->selectList->size(), 3);
   ASSERT(!stmt->selectList->at(1)->distinct);
   ASSERT(stmt->selectList->at(2)->distinct);
-
-  delete result;
 }
 
 TEST(OrderByTest) {
@@ -128,8 +118,6 @@ TEST(OrderByTest) {
 
   ASSERT_EQ(stmt->order->at(1)->type, kOrderDesc);
   ASSERT_STREQ(stmt->order->at(1)->expr->name, "city");
-
-  delete result;
 }
 
 TEST(SelectBetweenTest) {
@@ -144,7 +132,7 @@ TEST(SelectBetweenTest) {
   Expr* where = stmt->whereClause;
   ASSERT_NOTNULL(where);
   ASSERT(where->isType(kExprOperator));
-  ASSERT_EQ(where->opType, Expr::BETWEEN);
+  ASSERT_EQ(where->opType, kOpBetween);
 
   ASSERT_STREQ(where->expr->getName(), "grade");
   ASSERT(where->expr->isType(kExprColumnRef));
@@ -154,8 +142,6 @@ TEST(SelectBetweenTest) {
   ASSERT_EQ(where->exprList->at(0)->ival, 1);
   ASSERT(where->exprList->at(1)->isType(kExprColumnRef));
   ASSERT_STREQ(where->exprList->at(1)->getName(), "c");
-
-  delete result;
 }
 
 TEST(SelectConditionalSelectTest) {
@@ -169,7 +155,7 @@ TEST(SelectConditionalSelectTest) {
   Expr* where = stmt->whereClause;
   ASSERT_NOTNULL(where);
   ASSERT(where->isType(kExprOperator));
-  ASSERT_EQ(where->opType, Expr::AND);
+  ASSERT_EQ(where->opType, kOpAnd);
 
   // a = (SELECT ...)
   Expr* cond1 = where->expr;
@@ -189,13 +175,11 @@ TEST(SelectConditionalSelectTest) {
 
   // EXISTS (SELECT ...)
   Expr* cond2 = where->expr2;
-  ASSERT_EQ(cond2->opType, Expr::EXISTS);
+  ASSERT_EQ(cond2->opType, kOpExists);
   ASSERT_NOTNULL(cond2->select);
 
   SelectStatement* ex_select = cond2->select;
   ASSERT_STREQ(ex_select->fromTable->getName(), "test");
-
-  delete result;
 }
 
 TEST(SelectCaseWhen) {
@@ -216,10 +200,8 @@ TEST(SelectCaseWhen) {
   Expr* caseExpr = func->exprList->at(0);
   ASSERT_NOTNULL(caseExpr);
   ASSERT(caseExpr->isType(kExprOperator));
-  ASSERT_EQ(caseExpr->opType, Expr::CASE);
+  ASSERT_EQ(caseExpr->opType, kOpCase);
   ASSERT(caseExpr->expr->isType(kExprOperator));
   ASSERT(caseExpr->expr->isSimpleOp('='));
   ASSERT_EQ(caseExpr->exprList->size(), 2);
-
-  delete result;
 }
diff --git a/test/sql_asserts.h b/test/sql_asserts.h
index bf3a703..13496cd 100644
--- a/test/sql_asserts.h
+++ b/test/sql_asserts.h
@@ -3,20 +3,21 @@
 
 
 #define TEST_PARSE_SQL_QUERY(query, result, numStatements) \
-	const SQLParserResult* result = SQLParser::parseSQLString(query); \
-	ASSERT(result->isValid()); \
-	ASSERT_EQ(result->size(), numStatements);
+	hsql::SQLParserResult result; \
+  hsql::SQLParser::parseSQLString(query, &result); \
+	ASSERT(result.isValid()); \
+	ASSERT_EQ(result.size(), numStatements);
 
 
 #define TEST_PARSE_SINGLE_SQL(query, stmtType, stmtClass, result, outputVar) \
 	TEST_PARSE_SQL_QUERY(query, result, 1); \
-    ASSERT_EQ(result->getStatement(0)->type(), stmtType); \
-    const stmtClass* outputVar = (const stmtClass*) result->getStatement(0);
+    ASSERT_EQ(result.getStatement(0)->type(), stmtType); \
+    const stmtClass* outputVar = (const stmtClass*) result.getStatement(0);
 
 
 #define TEST_CAST_STMT(result, stmt_index, stmtType, stmtClass, outputVar) \
-    ASSERT_EQ(result->getStatement(stmt_index)->type(), stmtType); \
-    const stmtClass* outputVar = (const stmtClass*) result->getStatement(stmt_index);
+    ASSERT_EQ(result.getStatement(stmt_index)->type(), stmtType); \
+    const stmtClass* outputVar = (const stmtClass*) result.getStatement(stmt_index);
 
 
 #endif
diff --git a/test/sql_grammar_test.cpp b/test/sql_grammar_test.cpp
index 3bfecc8..0daf0c0 100644
--- a/test/sql_grammar_test.cpp
+++ b/test/sql_grammar_test.cpp
@@ -79,23 +79,22 @@ TEST(AutoGrammarTest) {
     start = std::chrono::system_clock::now();
 
     // Parsing
-    SQLParserResult* result = SQLParser::parseSQLString(sql.c_str());
+    SQLParserResult result;
+    SQLParser::parseSQLString(sql.c_str(), &result);
 
     end = std::chrono::system_clock::now();
     std::chrono::duration<double> elapsed_seconds = end - start;
     double us = elapsed_seconds.count() * 1000 * 1000;
 
-    if (expectFalse == result->isValid()) {
+    if (expectFalse == result.isValid()) {
       printf("\033[0;31m{  failed}\033[0m\n");
-      printf("\t\033[0;31m%s (L%d:%d)\n\033[0m", result->errorMsg(), result->errorLine(), result->errorColumn());
+      printf("\t\033[0;31m%s (L%d:%d)\n\033[0m", result.errorMsg(), result.errorLine(), result.errorColumn());
       printf("\t%s\n", sql.c_str());
       numFailed++;
     } else {
       // TODO: indicate whether expectFalse was set
       printf("\033[0;32m{      ok} (%.1fus)\033[0m %s\n", us, sql.c_str());
     }
-
-    delete result;
   }
 
   if (numFailed == 0) {
diff --git a/test/sql_tests.cpp b/test/sql_tests.cpp
index 89ccf60..fce09d9 100644
--- a/test/sql_tests.cpp
+++ b/test/sql_tests.cpp
@@ -3,36 +3,40 @@
  */
 
 #include "thirdparty/microtest/microtest.h"
-#include "sql_asserts.h"
+
 #include "SQLParser.h"
-#include "sqlhelper.h"
+#include "util/sqlhelper.h"
+
+#include "sql_asserts.h"
 
 using namespace hsql;
 
 
 TEST(DeleteStatementTest) {
-  const SQLParserResult* result = SQLParser::parseSQLString("DELETE FROM students WHERE grade > 2.0;");
-  ASSERT(result->isValid());
-  ASSERT_EQ(result->size(), 1);
-  ASSERT(result->getStatement(0)->type() == kStmtDelete);
+  SQLParserResult result;
+  SQLParser::parseSQLString("DELETE FROM students WHERE grade > 2.0;", &result);
 
-  const DeleteStatement* stmt = (const DeleteStatement*) result->getStatement(0);
+  ASSERT(result.isValid());
+  ASSERT_EQ(result.size(), 1);
+  ASSERT(result.getStatement(0)->type() == kStmtDelete);
+
+  const DeleteStatement* stmt = (const DeleteStatement*) result.getStatement(0);
   ASSERT_STREQ(stmt->tableName, "students");
   ASSERT_NOTNULL(stmt->expr);
   ASSERT(stmt->expr->isType(kExprOperator));
   ASSERT_STREQ(stmt->expr->expr->name, "grade");
   ASSERT_EQ(stmt->expr->expr2->fval, 2.0);
-
-  delete result;
 }
 
 TEST(CreateStatementTest) {
-  const SQLParserResult* result = SQLParser::parseSQLString("CREATE TABLE students (name TEXT, student_number INT, city INTEGER, grade DOUBLE)");
-  ASSERT(result->isValid());
-  ASSERT_EQ(result->size(), 1);
-  ASSERT_EQ(result->getStatement(0)->type(), kStmtCreate);
+  SQLParserResult result;
+  SQLParser::parseSQLString("CREATE TABLE students (name TEXT, student_number INT, city INTEGER, grade DOUBLE)", &result);
 
-  const CreateStatement* stmt = (const CreateStatement*) result->getStatement(0);
+  ASSERT(result.isValid());
+  ASSERT_EQ(result.size(), 1);
+  ASSERT_EQ(result.getStatement(0)->type(), kStmtCreate);
+
+  const CreateStatement* stmt = (const CreateStatement*) result.getStatement(0);
   ASSERT_EQ(stmt->type, CreateStatement::kTable);
   ASSERT_STREQ(stmt->tableName, "students");
   ASSERT_NOTNULL(stmt->columns);
@@ -45,18 +49,18 @@ TEST(CreateStatementTest) {
   ASSERT_EQ(stmt->columns->at(1)->type, ColumnDefinition::INT);
   ASSERT_EQ(stmt->columns->at(2)->type, ColumnDefinition::INT);
   ASSERT_EQ(stmt->columns->at(3)->type, ColumnDefinition::DOUBLE);
-
-  delete result;
 }
 
 
 TEST(UpdateStatementTest) {
-  const SQLParserResult* result = SQLParser::parseSQLString("UPDATE students SET grade = 5.0, name = 'test' WHERE name = 'Max Mustermann';");
-  ASSERT(result->isValid());
-  ASSERT_EQ(result->size(), 1);
-  ASSERT_EQ(result->getStatement(0)->type(), kStmtUpdate);
+  SQLParserResult result;
+  SQLParser::parseSQLString("UPDATE students SET grade = 5.0, name = 'test' WHERE name = 'Max Mustermann';", &result);
 
-  const UpdateStatement* stmt = (const UpdateStatement*) result->getStatement(0);
+  ASSERT(result.isValid());
+  ASSERT_EQ(result.size(), 1);
+  ASSERT_EQ(result.getStatement(0)->type(), kStmtUpdate);
+
+  const UpdateStatement* stmt = (const UpdateStatement*) result.getStatement(0);
   ASSERT_NOTNULL(stmt->table);
   ASSERT_STREQ(stmt->table->name, "students");
 
@@ -74,9 +78,6 @@ TEST(UpdateStatementTest) {
   ASSERT(stmt->where->isSimpleOp('='));
   ASSERT_STREQ(stmt->where->expr->name, "name");
   ASSERT_STREQ(stmt->where->expr2->name, "Max Mustermann");
-  \
-
-  delete result;
 }
 
 
@@ -90,8 +91,6 @@ TEST(InsertStatementTest) {
 
   ASSERT_EQ(stmt->values->size(), 4);
   // TODO
-
-  delete result;
 }
 
 
@@ -106,66 +105,26 @@ TEST(DropTableStatementTest) {
   ASSERT_EQ(stmt->type, DropStatement::kTable);
   ASSERT_NOTNULL(stmt->name);
   ASSERT_STREQ(stmt->name, "students");
-
-  delete result;
 }
 
+TEST(ReleaseStatementTest) {
+  TEST_PARSE_SINGLE_SQL(
+    "SELECT * FROM students;",
+    kStmtSelect,
+    SelectStatement,
+    result,
+    stmt);
 
-TEST(PrepareStatementTest) {
-  std::string query = "PREPARE test {"
-                      "INSERT INTO test VALUES(?);"
-                      "SELECT ?, test FROM test WHERE c1 = ?;"
-                      "};"
-                      "PREPARE stmt: SELECT * FROM data WHERE c1 = ?;"
-                      "DEALLOCATE PREPARE stmt;";
+  ASSERT_EQ(1, result.size());
+  ASSERT_NULL(stmt->whereClause);
 
-  TEST_PARSE_SQL_QUERY(query, result, 3);
+  std::vector<SQLStatement*> statements = result.releaseStatements();
 
-  TEST_CAST_STMT(result, 0, kStmtPrepare, PrepareStatement, prep1);
-  TEST_CAST_STMT(result, 1, kStmtPrepare, PrepareStatement, prep2);
-  TEST_CAST_STMT(result, 2, kStmtDrop, DropStatement, drop);
+  ASSERT_EQ(0, result.size());
 
-  // Prepare Statement #1
-  ASSERT_STREQ(prep1->name, "test");
-  ASSERT_EQ(prep1->placeholders.size(), 3);
-  ASSERT_EQ(prep1->query->size(), 2);
-
-  TEST_CAST_STMT(prep1->query, 0, kStmtInsert, InsertStatement, insert);
-  TEST_CAST_STMT(prep1->query, 1, kStmtSelect, SelectStatement, select);
-
-  ASSERT(insert->values->at(0)->isType(kExprPlaceholder));
-  ASSERT(select->selectList->at(0)->isType(kExprPlaceholder));
-  ASSERT(select->whereClause->expr2->isType(kExprPlaceholder));
-
-  // Check IDs of placeholders
-  ASSERT_EQ(insert->values->at(0)->ival, 0);
-  ASSERT_EQ(insert->values->at(0), prep1->placeholders[0]);
-
-  ASSERT_EQ(select->selectList->at(0)->ival, 1);
-  ASSERT_EQ(select->selectList->at(0), prep1->placeholders[1]);
-
-  ASSERT_EQ(select->whereClause->expr2->ival, 2);
-  ASSERT_EQ(select->whereClause->expr2, prep1->placeholders[2]);
-
-  // Prepare Statement #2
-  ASSERT_STREQ(prep2->name, "stmt");
-  ASSERT_EQ(prep2->placeholders.size(), 1);
-
-  // Deallocate Statement
-  ASSERT_EQ(drop->type, DropStatement::kPreparedStatement);
-  ASSERT_STREQ(drop->name, "stmt");
-
-  delete result;
+  for (SQLStatement* stmt : statements) {
+    delete stmt;
+  }
 }
 
-
-TEST(ExecuteStatementTest) {
-  TEST_PARSE_SINGLE_SQL("EXECUTE test(1, 2);", kStmtExecute, ExecuteStatement, result, stmt);
-
-  ASSERT_STREQ(stmt->name, "test");
-  ASSERT_EQ(stmt->parameters->size(), 2);
-
-  delete result;
-}
-
-TEST_MAIN();
\ No newline at end of file
+TEST_MAIN();
diff --git a/test/tpc_h_tests.cpp b/test/tpc_h_tests.cpp
index 9da1b13..310972d 100644
--- a/test/tpc_h_tests.cpp
+++ b/test/tpc_h_tests.cpp
@@ -1,7 +1,9 @@
 #include "thirdparty/microtest/microtest.h"
-#include "sql_asserts.h"
+
 #include "SQLParser.h"
-#include "sqlhelper.h"
+#include "util/sqlhelper.h"
+
+#include "sql_asserts.h"
 
 #include <string>
 #include <fstream>
@@ -37,15 +39,15 @@ TEST(TPCHQueryGrammarTests) {
   for (const std::string& file_path : files) {
     std::string query = readFileContents(file_path);
 
-    SQLParserResult* result = SQLParser::parseSQLString(query.c_str());
-    if (!result->isValid()) {
+    SQLParserResult result;
+    SQLParser::parseSQLString(query.c_str(), &result);
+    if (!result.isValid()) {
       mt::printFailed(file_path.c_str());
-      printf("%s           %s (L%d:%d)%s\n", mt::red(), result->errorMsg(), result->errorLine(), result->errorColumn(), mt::def());
+      printf("%s           %s (L%d:%d)%s\n", mt::red(), result.errorMsg(), result.errorLine(), result.errorColumn(), mt::def());
       ++testsFailed;
     } else {
       mt::printOk(file_path.c_str());
     }
-    delete result;
   }
   ASSERT_EQ(testsFailed, 0);
 }
@@ -53,11 +55,12 @@ TEST(TPCHQueryGrammarTests) {
 TEST(TPCHQueryDetailTest) {
   std::string query = readFileContents("test/queries/tpc-h-16-22.sql");
 
-  SQLParserResult* result = SQLParser::parseSQLString(query.c_str());
-  ASSERT(result->isValid());
-  ASSERT_EQ(result->size(), 7);
+  SQLParserResult result;
+  SQLParser::parseSQLString(query.c_str(), &result);
+  ASSERT(result.isValid());
+  ASSERT_EQ(result.size(), 7);
 
-  const SQLStatement* stmt20 = result->getStatement(4);
+  const SQLStatement* stmt20 = result.getStatement(4);
   ASSERT_EQ(stmt20->type(), kStmtSelect);
 
   const SelectStatement* select20 = (const SelectStatement*) stmt20;
@@ -69,18 +72,18 @@ TEST(TPCHQueryDetailTest) {
   Expr* where = select20->whereClause;
   ASSERT_NOTNULL(where);
   ASSERT(where->isType(kExprOperator));
-  ASSERT_EQ(where->opType, Expr::AND);
+  ASSERT_EQ(where->opType, kOpAnd);
 
   Expr* andExpr2 = where->expr;
   ASSERT_NOTNULL(andExpr2);
   ASSERT(andExpr2->isType(kExprOperator));
-  ASSERT_EQ(andExpr2->opType, Expr::AND);
+  ASSERT_EQ(andExpr2->opType, kOpAnd);
 
   // Test IN expression.
   Expr* inExpr = andExpr2->expr;
   ASSERT_NOTNULL(inExpr);
   ASSERT(inExpr->isType(kExprOperator));
-  ASSERT_EQ(inExpr->opType, Expr::IN);
+  ASSERT_EQ(inExpr->opType, kOpIn);
 
   ASSERT_STREQ(inExpr->expr->getName(), "S_SUPPKEY");
   ASSERT_NOTNULL(inExpr->select);
@@ -93,6 +96,4 @@ TEST(TPCHQueryDetailTest) {
   ASSERT_EQ(select20->order->size(), 1);
   ASSERT(select20->order->at(0)->expr->isType(kExprColumnRef));
   ASSERT_STREQ(select20->order->at(0)->expr->getName(), "S_NAME");
-
-  delete result;
-}
\ No newline at end of file
+}