beedb/include/plan/logical/node/table.h

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2022-04-04 20:25:01 +02:00
/*------------------------------------------------------------------------------*
* Architecture & Implementation of DBMS *
*------------------------------------------------------------------------------*
* Copyright 2022 Databases and Information Systems Group TU Dortmund *
* Visit us at *
* http://dbis.cs.tu-dortmund.de/cms/en/home/ *
* *
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS *
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, *
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL *
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR *
* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, *
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR *
* OTHER DEALINGS IN THE SOFTWARE. *
* *
* Authors: *
* Maximilian Berens <maximilian.berens@tu-dortmund.de> *
* Roland Kühn <roland.kuehn@cs.tu-dortmund.de> *
* Jan Mühlig <jan.muehlig@tu-dortmund.de> *
*------------------------------------------------------------------------------*
*/
#pragma once
#include <database.h>
#include <exception/logical_exception.h>
#include <string>
namespace beedb::plan::logical
{
class TableReference
{
public:
TableReference(const std::string &name, const std::string &alias) : _table_name(name), _table_alias(alias)
{
}
TableReference(TableReference &&) noexcept = default;
TableReference(const TableReference &) = default;
~TableReference() = default;
[[nodiscard]] const std::string &table_name() const
{
return _table_name;
}
[[nodiscard]] const std::string &table_alias() const
{
return _table_alias;
}
bool operator==(const std::string &name) const
{
return _table_name == name || _table_alias == name;
}
private:
std::string _table_name;
std::string _table_alias;
};
class TableMap
{
public:
TableMap() = default;
~TableMap() = default;
void insert(table::Table *table, const std::string &table_alias)
{
_table_alias_to_name.insert(std::make_pair(table_alias, table->name()));
for (const auto &term : table->schema().terms())
{
const auto &column_name = term.get<expression::Attribute>().column_name();
if (_attribute_name_to_table_alias.find(column_name) == _attribute_name_to_table_alias.end())
{
_attribute_name_to_table_alias.insert(
std::make_pair(column_name, std::vector<std::string>{table_alias}));
}
else
{
_attribute_name_to_table_alias.at(column_name).push_back(table_alias);
}
}
}
void ensure_table_exists(const std::string &name)
{
if (_table_alias_to_name.find(name) == _table_alias_to_name.end())
{
throw exception::TableNotFoundException(name);
}
}
void check_and_replace_table(expression::Attribute &attribute)
{
if (attribute.table_name().has_value())
{
ensure_table_exists(attribute.table_name().value());
}
else if (attribute.is_asterisk() == false)
{
if (_attribute_name_to_table_alias.find(attribute.column_name()) == _attribute_name_to_table_alias.end())
{
throw exception::CanNotResolveColumnException(attribute.column_name());
}
const auto &tables = _attribute_name_to_table_alias.at(attribute.column_name());
if (tables.size() != 1)
{
throw exception::CanNotResolveColumnException(attribute.column_name());
}
attribute.table_name(tables.front());
}
}
void check_and_replace_table(std::unique_ptr<expression::Operation> &operation)
{
expression::for_attribute(operation, [this](auto &attribute) { this->check_and_replace_table(attribute); });
}
std::vector<std::string> tables() const
{
std::vector<std::string> table_aliases;
table_aliases.reserve(_table_alias_to_name.size());
for (const auto &[_, name] : _table_alias_to_name)
{
table_aliases.push_back(name);
}
return table_aliases;
}
private:
std::unordered_map<std::string, std::string> _table_alias_to_name;
std::unordered_map<std::string, std::vector<std::string>> _attribute_name_to_table_alias;
};
} // namespace beedb::plan::logical