0
0
mirror of https://github.com/rbock/sqlpp11.git synced 2024-11-15 20:31:16 +08:00
sqlpp11/include/sqlpp11/select_pseudo_table.h
2013-11-01 15:25:52 +01:00

82 lines
2.7 KiB
C++

/*
* Copyright (c) 2013, Roland Bock
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
*
* Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above copyright notice, this
* list of conditions and the following disclaimer in the documentation and/or
* other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
* ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
* ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef SQLPP_SELECT_PSEUDO_TABLE_H
#define SQLPP_SELECT_PSEUDO_TABLE_H
#include <sqlpp11/no_value.h>
namespace sqlpp
{
// provide type information for sub-selects that are used as named expressions or tables
template<typename Expr>
struct select_column_spec_t
{
using _name_t = typename Expr::_name_t;
using _value_type = typename Expr::_value_type;
struct _column_type {};
};
template<
typename Select,
typename... NamedExpr
>
struct select_pseudo_table_t: public sqlpp::table_base_t<select_pseudo_table_t<
Select,
NamedExpr...>, select_column_spec_t<NamedExpr>...>
{
using _value_type = no_value_t;
select_pseudo_table_t(const Select& select):
_select(select)
{
}
select_pseudo_table_t(Select&& select):
_select(std::move(select))
{
}
select_pseudo_table_t(const select_pseudo_table_t& rhs) = default;
select_pseudo_table_t(select_pseudo_table_t&& rhs) = default;
select_pseudo_table_t& operator=(const select_pseudo_table_t& rhs) = default;
select_pseudo_table_t& operator=(select_pseudo_table_t&& rhs) = default;
~select_pseudo_table_t() = default;
template<typename Db>
void serialize(std::ostream& os, Db& db) const
{
static_assert(Db::_supports_select_as_table, "select as table not supported by current database");
_select.serialize(os, db);
}
Select _select;
};
}
#endif