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sqlpp11/include/sqlpp11/on.h
2013-10-05 17:35:40 +02:00

90 lines
2.5 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_ON_H
#define SQLPP_ON_H
#include <ostream>
#include <vector>
#include <sqlpp11/type_traits.h>
#include <sqlpp11/detail/serializable.h>
namespace sqlpp
{
template<typename Expr>
struct on_t
{
static_assert(is_expression_t<Expr>::value, "invalid expression argument in on()");
using _is_on = std::true_type;
template<typename Db>
void serialize(std::ostream& os, Db& db) const
{
os << " ON ";
_expr.serialize(os, db);
}
Expr _expr;
};
template<typename Db>
struct dynamic_on_t
{
using _is_on = std::true_type;
using _is_dynamic = std::true_type;
template<typename Expr>
void add(Expr&& expr)
{
static_assert(is_expression_t<typename std::decay<Expr>::type>::value, "invalid expression argument in on()");
_conditions.push_back(std::forward<Expr>(expr));
}
void serialize(std::ostream& os, Db& db) const
{
if (_conditions.empty())
return;
os << " ON ";
bool first = true;
for (const auto& condition : _conditions)
{
if (not first)
os << " AND ";
condition.serialize(os, db);
first = false;
}
}
std::vector<detail::serializable_t<Db>> _conditions;
};
}
#endif