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sqlpp11/include/sqlpp11/remove.h

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7.2 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_REMOVE_H
#define SQLPP_REMOVE_H
#include <sqlpp11/type_traits.h>
#include <sqlpp11/parameter_list.h>
#include <sqlpp11/prepared_remove.h>
#include <sqlpp11/vendor/noop.h>
#include <sqlpp11/vendor/single_table.h>
#include <sqlpp11/vendor/using.h>
#include <sqlpp11/vendor/where.h>
#include <sqlpp11/vendor/policy_update.h>
#include <sqlpp11/detail/arg_selector.h>
namespace sqlpp
{
namespace detail
{
template<typename Table, typename Using, typename Where>
struct check_remove_t
{
static_assert(is_where_t<Where>::value, "cannot run remove without having a where condition, use .where(true) to remove all rows");
static constexpr bool value = true;
};
}
// REMOVE
template<typename Database,
typename Table = vendor::no_single_table_t,
typename Using = vendor::no_using_t,
typename Where = vendor::no_where_t
>
struct remove_t
{
using _database_t = Database;
using _is_dynamic = typename std::conditional<std::is_same<Database, void>::value, std::false_type, std::true_type>::type;
template<typename Needle, typename Replacement, typename... Policies>
struct _policies_update_impl
{
using type = remove_t<Database, vendor::policy_update_t<Policies, Needle, Replacement>...>;
};
template<typename Needle, typename Replacement>
using _policies_update_t = typename _policies_update_impl<Needle, Replacement, Table, Using, Where>::type;
using _parameter_tuple_t = std::tuple<Table, Using, Where>;
using _parameter_list_t = typename make_parameter_list_t<remove_t>::type;
// Constructors
remove_t()
{}
template<typename Statement, typename T>
remove_t(Statement s, T t):
_table(detail::arg_selector<Table>::_(s._table, t)),
_using(detail::arg_selector<Using>::_(s._using, t)),
_where(detail::arg_selector<Where>::_(s._where, t))
{}
remove_t(const remove_t&) = default;
remove_t(remove_t&&) = default;
remove_t& operator=(const remove_t&) = default;
remove_t& operator=(remove_t&&) = default;
~remove_t() = default;
// type update functions
template<typename... Args>
auto using_(Args... args)
-> _policies_update_t<vendor::no_using_t, vendor::using_t<void, Args...>>
{
static_assert(is_noop_t<Using>::value, "cannot call using_()/dynamic_using() twice");
return { *this, vendor::using_t<void, Args...>{args...} };
}
template<typename... Args>
auto dynamic_using(Args... args)
-> _policies_update_t<vendor::no_using_t, vendor::using_t<_database_t, Args...>>
{
static_assert(is_noop_t<Using>::value, "cannot call using_()/dynamic_using() twice");
static_assert(not std::is_same<_database_t, void>::value, "dynamic_using must not be called in a static statement");
return { *this, vendor::using_t<_database_t, Args...>{args...} };
}
template<typename... Args>
auto where(Args... args)
-> _policies_update_t<vendor::no_where_t, vendor::where_t<void, Args...>>
{
static_assert(is_noop_t<Where>::value, "cannot call where()/dynamic_where() twice");
return { *this, vendor::where_t<void, Args...>{args...} };
}
template<typename... Args>
auto dynamic_where(Args... args)
-> _policies_update_t<vendor::no_where_t, vendor::where_t<_database_t, Args...>>
{
static_assert(is_noop_t<Where>::value, "cannot call where()/dynamic_where() twice");
static_assert(not std::is_same<_database_t, void>::value, "dynamic_where must not be called in a static statement");
return { *this, vendor::where_t<_database_t, Args...>{args...} };
}
// value adding methods
template<typename... Args>
void add_using(Args... args)
{
static_assert(is_using_t<Using>::value, "cannot call add_using() before dynamic_using()");
static_assert(is_dynamic_t<Using>::value, "cannot call add_using() before dynamic_using()");
return _using.add_using(args...);
}
template<typename... Args>
void add_where(Args... args)
{
static_assert(is_where_t<Where>::value, "cannot call add_where() before dynamic_where()");
static_assert(is_dynamic_t<Where>::value, "cannot call add_where() before dynamic_where()");
return _where.add_where(*this, args...);
}
// run and prepare
static constexpr size_t _get_static_no_of_parameters()
{
return _parameter_list_t::size::value;
}
size_t _get_no_of_parameters() const
{
return _parameter_list_t::size::value;
}
template<typename Db>
std::size_t _run(Db& db) const
{
static_assert(_get_static_no_of_parameters() == 0, "cannot run remove directly with parameters, use prepare instead");
//static_assert(detail::check_remove_t<Policies...>::value, "Cannot run this remove expression");
return db.remove(*this);
}
template<typename Db>
auto _prepare(Db& db) const
-> prepared_remove_t<Db, remove_t>
{
//static_assert(detail::check_remove_t<Policies...>::value, "Cannot run this remove expression");
return {{}, db.prepare_remove(*this)};
}
Table _table;
Using _using;
Where _where;
};
namespace vendor
{
template<typename Context, typename Database, typename... Policies>
struct serializer_t<Context, remove_t<Database, Policies...>>
{
using T = remove_t<Database, Policies...>;
static Context& _(const T& t, Context& context)
{
context << "DELETE FROM ";
serialize(t._table, context);
serialize(t._using, context);
serialize(t._where, context);
return context;
}
};
}
template<typename Table>
constexpr auto remove_from(Table table)
-> remove_t<void, vendor::single_table_t<void, Table>>
{
return { remove_t<void>(), vendor::single_table_t<void, Table>{table} };
}
template<typename Database, typename Table>
constexpr auto dynamic_remove_from(const Database&, Table table)
-> remove_t<Database, vendor::single_table_t<void, Table>>
{
return { remove_t<Database>(), vendor::single_table_t<void, Table>{table} };
}
}
#endif