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sqlpp11/include/sqlpp11/update_list.h
2015-02-17 08:03:19 +01:00

254 lines
9.2 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_UPDATE_LIST_H
#define SQLPP_UPDATE_LIST_H
#include <sqlpp11/type_traits.h>
#include <sqlpp11/detail/type_set.h>
#include <sqlpp11/interpret_tuple.h>
#include <sqlpp11/interpretable_list.h>
namespace sqlpp
{
// UPDATE ASSIGNMENTS DATA
template<typename Database, typename... Assignments>
struct update_list_data_t
{
update_list_data_t(Assignments... assignments):
_assignments(assignments...)
{}
update_list_data_t(const update_list_data_t&) = default;
update_list_data_t(update_list_data_t&&) = default;
update_list_data_t& operator=(const update_list_data_t&) = default;
update_list_data_t& operator=(update_list_data_t&&) = default;
~update_list_data_t() = default;
std::tuple<Assignments...> _assignments;
interpretable_list_t<Database> _dynamic_assignments;
};
struct assert_no_unknown_tables_in_update_assignments_t
{
using type = std::false_type;
template<typename T = void>
static void _()
{
static_assert(wrong_t<T>::value, "at least one update assignment requires a table which is otherwise not known in the statement");
}
};
// UPDATE ASSIGNMENTS
template<typename Database, typename... Assignments>
struct update_list_t
{
using _traits = make_traits<no_value_t, tag::is_update_list>;
using _nodes = detail::type_vector<Assignments...>;
using _is_dynamic = is_database<Database>;
// Data
using _data_t = update_list_data_t<Database, Assignments...>;
// Member implementation with data and methods
template <typename Policies>
struct _impl_t
{
template<typename Assignment>
void add_ntc(Assignment assignment)
{
add<Assignment, std::false_type>(assignment);
}
template<typename Assignment, typename TableCheckRequired = std::true_type>
void add(Assignment assignment)
{
static_assert(_is_dynamic::value, "add must not be called for static from()");
static_assert(is_assignment_t<Assignment>::value, "invalid assignment argument in add()");
using _assigned_columns = detail::make_type_set_t<lhs_t<Assignments>...>;
static_assert(not detail::is_element_of<lhs_t<Assignment>, _assigned_columns>::value, "Must not assign value to column twice");
static_assert(logic::not_t<must_not_update_t, lhs_t<Assignment>>::value, "add() argument must not be updated");
static_assert(TableCheckRequired::value or Policies::template _no_unknown_tables<Assignment>::value, "assignment uses tables unknown to this statement in add()");
using _serialize_check = sqlpp::serialize_check_t<typename Database::_serializer_context_t, Assignment>;
_serialize_check::_();
using ok = logic::all_t<
_is_dynamic::value,
is_assignment_t<Assignment>::value,
_serialize_check::type::value>;
_add_impl(assignment, ok()); // dispatch to prevent compile messages after the static_assert
}
private:
template<typename Assignment>
void _add_impl(Assignment assignment, const std::true_type&)
{
return _data._dynamic_assignments.emplace_back(assignment);
}
template<typename Assignment>
void _add_impl(Assignment assignment, const std::false_type&);
public:
_data_t _data;
};
// Base template to be inherited by the statement
template<typename Policies>
struct _base_t
{
using _data_t = update_list_data_t<Database, Assignments...>;
_impl_t<Policies> assignments;
_impl_t<Policies>& operator()() { return assignments; }
const _impl_t<Policies>& operator()() const { return assignments; }
template<typename T>
static auto _get_member(T t) -> decltype(t.assignments)
{
return t.assignments;
}
using _consistency_check = typename std::conditional<Policies::template _no_unknown_tables<update_list_t>::value,
consistent_t,
assert_no_unknown_tables_in_update_assignments_t>::type;
};
};
struct assert_update_assignments_t
{
using type = std::false_type;
template<typename T = void>
static void _()
{
static_assert(wrong_t<T>::value, "update assignments required, i.e. set(...)");
}
};
struct no_update_list_t
{
using _traits = make_traits<no_value_t, tag::is_where>;
using _nodes = detail::type_vector<>;
// Data
using _data_t = no_data_t;
// Member implementation with data and methods
template<typename Policies>
struct _impl_t
{
_data_t _data;
};
// Base template to be inherited by the statement
template<typename Policies>
struct _base_t
{
using _data_t = no_data_t;
_impl_t<Policies> no_assignments;
_impl_t<Policies>& operator()() { return no_assignments; }
const _impl_t<Policies>& operator()() const { return no_assignments; }
template<typename T>
static auto _get_member(T t) -> decltype(t.no_assignments)
{
return t.no_assignments;
}
using _database_t = typename Policies::_database_t;
template<typename... T>
using _check = logic::all_t<is_assignment_t<T>::value...>;
template<typename Check, typename T>
using _new_statement_t = new_statement_t<Check::value, Policies, no_update_list_t, T>;
using _consistency_check = assert_update_assignments_t;
template<typename... Assignments>
auto set(Assignments... assignments) const
-> _new_statement_t<_check<Assignments...>, update_list_t<void, Assignments...>>
{
static_assert(sizeof...(Assignments), "at least one assignment expression required in set()");
static_assert(_check<Assignments...>::value, "at least one argument is not an assignment in set()");
return _set_impl<void>(_check<Assignments...>{}, assignments...);
}
template<typename... Assignments>
auto dynamic_set(Assignments... assignments) const
-> _new_statement_t<_check<Assignments...>, update_list_t<_database_t, Assignments...>>
{
static_assert(not std::is_same<_database_t, void>::value, "dynamic_set() must not be called in a static statement");
static_assert(_check<Assignments...>::value, "at least one argument is not an assignment in set()");
return _set_impl<_database_t>(_check<Assignments...>{}, assignments...);
}
private:
template<typename Database, typename... Assignments>
auto _set_impl(const std::false_type&, Assignments... assignments) const
-> bad_statement;
template<typename Database, typename... Assignments>
auto _set_impl(const std::true_type&, Assignments... assignments) const
-> _new_statement_t<std::true_type, update_list_t<Database, Assignments...>>
{
static_assert(not detail::has_duplicates<lhs_t<Assignments>...>::value, "at least one duplicate column detected in set()");
static_assert(logic::none_t<must_not_update_t<lhs_t<Assignments>>::value...>::value, "at least one assignment is prohibited by its column definition in set()");
using _column_required_tables = detail::make_joined_set_t<required_tables_of<lhs_t<Assignments>>...>;
static_assert(sizeof...(Assignments) ? (_column_required_tables::size::value == 1) : true, "set() contains assignments for columns from more than one table");
return { static_cast<const derived_statement_t<Policies>&>(*this), update_list_data_t<Database, Assignments...>{assignments...} };
}
};
};
// Interpreters
template<typename Context, typename Database, typename... Assignments>
struct serializer_t<Context, update_list_data_t<Database, Assignments...>>
{
using _serialize_check = serialize_check_of<Context, Assignments...>;
using T = update_list_data_t<Database, Assignments...>;
static Context& _(const T& t, Context& context)
{
context << " SET ";
interpret_tuple(t._assignments, ",", context);
if (sizeof...(Assignments) and not t._dynamic_assignments.empty())
context << ',';
interpret_list(t._dynamic_assignments, ',', context);
return context;
}
};
}
#endif