beedb/include/plan/logical/node/projection_node.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 "node_interface.h"
#include <sstream>
namespace beedb::plan::logical
{
class ProjectionNode final : public UnaryNode
{
public:
explicit ProjectionNode(Schema &&schema) : UnaryNode("Projection"), _schema(std::move(schema))
{
}
~ProjectionNode() override = default;
const Schema &check_and_emit_schema(TableMap &tables) override
{
const auto &child_schema = child()->check_and_emit_schema(tables);
// TODO: Check
for (auto &term : _schema)
{
if (term.is_attribute() && term.is_generated() == false)
{
tables.check_and_replace_table(term.get<expression::Attribute>());
}
}
// TODO: Rebuild schema or use own schema just for order?
Schema real_schema;
for (auto &term : _schema)
{
if (term.is_attribute())
{
auto &attribute = term.get<expression::Attribute>();
const auto asterisk_has_table = attribute.table_name().has_value();
if (attribute.is_asterisk())
{
for (const auto &child_term : child_schema)
{
if (asterisk_has_table == false)
{
real_schema.push_back(child_term);
}
else if (child_term.is_attribute() &&
child_term.get<expression::Attribute>().table_name() == attribute.table_name())
{
real_schema.emplace_back(expression::Attribute{child_term.get<expression::Attribute>(),
attribute.is_print_table_name()});
}
}
}
else
{
real_schema.emplace_back(std::move(term));
}
}
else
{
real_schema.emplace_back(std::move(term));
}
}
_schema = std::move(real_schema);
return _schema;
}
[[nodiscard]] const Schema &schema() const override
{
return _schema;
}
private:
Schema _schema;
};
} // namespace beedb::plan::logical