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sqlpp11/include/sqlpp11/in.h
rbock f029e5993b Allow in() and not_in() to have zero arguments
This is then equivalent to in(value_list(some_empty_vector)) and
not_in(value_list(some_empty_vector):

tab.a.in() evaluates to false
tab.a.not_in() evaluates to true
2015-12-19 15:15:04 +01:00

136 lines
4.1 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_IN_H
#define SQLPP_IN_H
#include <sqlpp11/type_traits.h>
#include <sqlpp11/char_sequence.h>
#include <sqlpp11/data_types/boolean.h>
#include <sqlpp11/in_fwd.h>
#include <sqlpp11/detail/type_set.h>
namespace sqlpp
{
struct in_alias_t
{
struct _alias_t
{
static constexpr const char _literal[] = "in_";
using _name_t = sqlpp::make_char_sequence<sizeof(_literal), _literal>;
template <typename T>
struct _member_t
{
T in;
};
};
};
template <typename Operand, typename... Args>
struct in_t : public expression_operators<in_t<Operand, Args...>, boolean>,
public alias_operators<in_t<Operand, Args...>>
{
using _traits = make_traits<boolean, tag::is_expression, tag::is_selectable>;
using _nodes = detail::type_vector<Operand, Args...>;
using _auto_alias_t = in_alias_t;
in_t(Operand operand, Args... args) : _operand(operand), _args(args...)
{
}
in_t(const in_t&) = default;
in_t(in_t&&) = default;
in_t& operator=(const in_t&) = default;
in_t& operator=(in_t&&) = default;
~in_t() = default;
Operand _operand;
std::tuple<Args...> _args;
};
template <typename Context, typename Operand, typename... Args>
struct serializer_t<Context, in_t<Operand, Args...>>
{
using _serialize_check = serialize_check_of<Context, Args...>;
using T = in_t<Operand, Args...>;
static Context& _(const T& t, Context& context)
{
serialize(t._operand, context);
context << " IN(";
if (sizeof...(Args) == 1)
serialize(std::get<0>(t._args), context);
else
interpret_tuple(t._args, ',', context);
context << ')';
return context;
}
};
template <typename Context, typename Operand>
struct serializer_t<Context, in_t<Operand>>
{
using _serialize_check = consistent_t;
using T = in_t<Operand>;
static Context& _(const T&, Context& context)
{
serialize(boolean_operand{false}, context);
return context;
}
};
template <typename Container>
struct value_list_t;
template <typename Context, typename Operand, typename Container>
struct serializer_t<Context, in_t<Operand, value_list_t<Container>>>
{
using _serialize_check = serialize_check_of<Context, value_list_t<Container>>;
using T = in_t<Operand, value_list_t<Container>>;
static Context& _(const T& t, Context& context)
{
const auto& value_list = std::get<0>(t._args);
if (value_list._container.empty())
{
serialize(boolean_operand{false}, context);
}
else
{
serialize(t._operand, context);
context << " IN(";
serialize(value_list, context);
context << ')';
}
return context;
}
};
}
#endif