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sqlpp11/include/sqlpp11/group_by.h
rbock 09f23cea0a Reformatted using clang-format
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2015-09-13 21:33:19 +02:00

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/*
* 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_GROUP_BY_H
#define SQLPP_GROUP_BY_H
#include <tuple>
#include <sqlpp11/type_traits.h>
#include <sqlpp11/expression.h>
#include <sqlpp11/interpret_tuple.h>
#include <sqlpp11/interpretable_list.h>
#include <sqlpp11/policy_update.h>
#include <sqlpp11/logic.h>
namespace sqlpp
{
// GROUP BY DATA
template <typename Database, typename... Expressions>
struct group_by_data_t
{
group_by_data_t(Expressions... expressions) : _expressions(expressions...)
{
}
group_by_data_t(const group_by_data_t&) = default;
group_by_data_t(group_by_data_t&&) = default;
group_by_data_t& operator=(const group_by_data_t&) = default;
group_by_data_t& operator=(group_by_data_t&&) = default;
~group_by_data_t() = default;
std::tuple<Expressions...> _expressions;
interpretable_list_t<Database> _dynamic_expressions;
};
struct assert_no_unknown_tables_in_group_by_t
{
using type = std::false_type;
template <typename T = void>
static void _()
{
static_assert(wrong_t<T>::value,
"at least one group-by expression requires a table which is otherwise not known in the statement");
}
};
// GROUP BY
template <typename Database, typename... Expressions>
struct group_by_t
{
using _traits = make_traits<no_value_t, tag::is_group_by>;
using _nodes = detail::type_vector<Expressions...>;
using _is_dynamic = is_database<Database>;
// Data
using _data_t = group_by_data_t<Database, Expressions...>;
// Member implementation with data and methods
template <typename Policies>
struct _impl_t
{
template <typename Expression>
void add_ntc(Expression expression)
{
add<Expression, std::false_type>(expression);
}
template <typename Expression, typename TableCheckRequired = std::true_type>
void add(Expression expression)
{
static_assert(_is_dynamic::value, "add() must not be called for static group_by");
static_assert(is_expression_t<Expression>::value, "invalid expression argument in group_by::add()");
static_assert(TableCheckRequired::value or Policies::template _no_unknown_tables<Expression>::value,
"expression uses tables unknown to this statement in group_by::add()");
using _serialize_check = sqlpp::serialize_check_t<typename Database::_serializer_context_t, Expression>;
_serialize_check::_();
using ok = logic::all_t<_is_dynamic::value, is_expression_t<Expression>::value, _serialize_check::type::value>;
_add_impl(expression, ok()); // dispatch to prevent compile messages after the static_assert
}
private:
template <typename Expression>
void _add_impl(Expression expression, const std::true_type&)
{
return _data._dynamic_expressions.emplace_back(expression);
}
template <typename Expression>
void _add_impl(Expression expression, 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 = group_by_data_t<Database, Expressions...>;
_impl_t<Policies> group_by;
_impl_t<Policies>& operator()()
{
return group_by;
}
const _impl_t<Policies>& operator()() const
{
return group_by;
}
template <typename T>
static auto _get_member(T t) -> decltype(t.group_by)
{
return t.group_by;
}
using _consistency_check = typename std::conditional<Policies::template _no_unknown_tables<group_by_t>::value,
consistent_t,
assert_no_unknown_tables_in_group_by_t>::type;
};
};
// NO GROUP BY YET
struct no_group_by_t
{
using _traits = make_traits<no_value_t, tag::is_noop>;
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_group_by;
_impl_t<Policies>& operator()()
{
return no_group_by;
}
const _impl_t<Policies>& operator()() const
{
return no_group_by;
}
template <typename T>
static auto _get_member(T t) -> decltype(t.no_group_by)
{
return t.no_group_by;
}
using _database_t = typename Policies::_database_t;
template <typename... T>
using _check = logic::all_t<is_expression_t<T>::value...>;
template <typename Check, typename T>
using _new_statement_t = new_statement_t<Check::value, Policies, no_group_by_t, T>;
using _consistency_check = consistent_t;
template <typename... Expressions>
auto group_by(Expressions... expressions) const
-> _new_statement_t<_check<Expressions...>, group_by_t<void, Expressions...>>
{
static_assert(sizeof...(Expressions), "at least one expression (e.g. a column) required in group_by()");
static_assert(_check<Expressions...>::value, "at least one argument is not an expression in group_by()");
return _group_by_impl<void>(_check<Expressions...>{}, expressions...);
}
template <typename... Expressions>
auto dynamic_group_by(Expressions... expressions) const
-> _new_statement_t<_check<Expressions...>, group_by_t<_database_t, Expressions...>>
{
static_assert(not std::is_same<_database_t, void>::value,
"dynamic_group_by must not be called in a static statement");
static_assert(_check<Expressions...>::value, "at least one argument is not an expression in group_by()");
return _group_by_impl<_database_t>(_check<Expressions...>{}, expressions...);
}
private:
template <typename Database, typename... Expressions>
auto _group_by_impl(const std::false_type&, Expressions... expressions) const -> bad_statement;
template <typename Database, typename... Expressions>
auto _group_by_impl(const std::true_type&, Expressions... expressions) const
-> _new_statement_t<std::true_type, group_by_t<_database_t, Expressions...>>
{
static_assert(not detail::has_duplicates<Expressions...>::value,
"at least one duplicate argument detected in group_by()");
return {static_cast<const derived_statement_t<Policies>&>(*this),
group_by_data_t<Database, Expressions...>{expressions...}};
}
};
};
// Interpreters
template <typename Context, typename Database, typename... Expressions>
struct serializer_t<Context, group_by_data_t<Database, Expressions...>>
{
using _serialize_check = serialize_check_of<Context, Expressions...>;
using T = group_by_data_t<Database, Expressions...>;
static Context& _(const T& t, Context& context)
{
if (sizeof...(Expressions) == 0 and t._dynamic_expressions.empty())
return context;
context << " GROUP BY ";
interpret_tuple(t._expressions, ',', context);
if (sizeof...(Expressions) and not t._dynamic_expressions.empty())
context << ',';
interpret_list(t._dynamic_expressions, ',', context);
return context;
}
};
}
#endif