mirror of
https://github.com/rbock/sqlpp11.git
synced 2024-11-16 04:47:18 +08:00
b41f1add8c
This allows to select NULL via a case statement (seems to make more sense than disallowing it).
57 lines
1.9 KiB
C++
57 lines
1.9 KiB
C++
/*
|
|
* Copyright (c) 2013-2015, 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_NULL_H
|
|
#define SQLPP_NULL_H
|
|
|
|
#include <sqlpp11/data_types/no_value.h>
|
|
|
|
namespace sqlpp
|
|
{
|
|
struct null_t
|
|
{
|
|
using _traits = make_traits<no_value_t, tag::is_expression, tag::is_sql_null>;
|
|
using _nodes = detail::type_vector<>;
|
|
};
|
|
|
|
template <typename Context>
|
|
struct serializer_t<Context, null_t>
|
|
{
|
|
using _serialize_check = consistent_t;
|
|
using Operand = null_t;
|
|
|
|
static Context& _(const Operand&, Context& context)
|
|
{
|
|
context << "NULL";
|
|
return context;
|
|
}
|
|
};
|
|
|
|
constexpr null_t null = {};
|
|
}
|
|
|
|
#endif
|