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sqlpp11/include/sqlpp11/having.h

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9.1 KiB
C++

/*
* Copyright (c) 2013-2016, 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_HAVING_H
#define SQLPP_HAVING_H
#include <sqlpp11/type_traits.h>
#include <sqlpp11/value.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
{
// HAVING DATA
template <typename Database, typename Expression>
struct having_data_t
{
having_data_t(Expression expression) : _expression(expression)
{
}
having_data_t(const having_data_t&) = default;
having_data_t(having_data_t&&) = default;
having_data_t& operator=(const having_data_t&) = default;
having_data_t& operator=(having_data_t&&) = default;
~having_data_t() = default;
Expression _expression;
interpretable_list_t<Database> _dynamic_expressions;
};
SQLPP_PORTABLE_STATIC_ASSERT(
assert_no_unknown_tables_in_having_t,
"at least one having-expression requires a table which is otherwise not known in the statement");
// HAVING
template <typename Database, typename Expression>
struct having_t
{
using _traits = make_traits<no_value_t, tag::is_having>;
using _nodes = detail::type_vector<Expression>;
using _is_dynamic = is_database<Database>;
// Data
using _data_t = having_data_t<Database, Expression>;
// Member implementation with data and methods
template <typename Policies>
struct _impl_t
{
// workaround for msvc bug https://connect.microsoft.com/VisualStudio/Feedback/Details/2091069
_impl_t() = default;
_impl_t(const _data_t& data) : _data(data)
{
}
template <typename Expr>
void add_ntc(Expr expression)
{
add<Expr, std::false_type>(expression);
}
template <typename Expr, typename TableCheckRequired = std::true_type>
void add(Expr expression)
{
static_assert(_is_dynamic::value, "having::add() can only be called for dynamic_having");
static_assert(is_expression_t<Expr>::value, "invalid expression argument in having::add()");
static_assert(not TableCheckRequired::value or Policies::template _no_unknown_tables<Expr>::value,
"expression uses tables unknown to this statement in having::add()");
using _serialize_check = sqlpp::serialize_check_t<typename Database::_serializer_context_t, Expr>;
_serialize_check::_();
using ok = logic::all_t<_is_dynamic::value, is_expression_t<Expr>::value, _serialize_check::type::value>;
_add_impl(expression, ok()); // dispatch to prevent compile messages after the static_assert
}
private:
template <typename Expr>
void _add_impl(Expr expression, const std::true_type&)
{
return _data._dynamic_expressions.emplace_back(expression);
}
template <typename Expr>
void _add_impl(Expr 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 = having_data_t<Database, Expression>;
// workaround for msvc bug https://connect.microsoft.com/VisualStudio/Feedback/Details/2091069
template <typename... Args>
_base_t(Args&&... args)
: having{std::forward<Args>(args)...}
{
}
_impl_t<Policies> having;
_impl_t<Policies>& operator()()
{
return having;
}
const _impl_t<Policies>& operator()() const
{
return having;
}
template <typename T>
static auto _get_member(T t) -> decltype(t.having)
{
return t.having;
}
using _consistency_check = typename std::conditional<Policies::template _no_unknown_tables<having_t>::value,
consistent_t,
assert_no_unknown_tables_in_having_t>::type;
};
};
// NO HAVING YET
struct no_having_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
{
// workaround for msvc bug https://connect.microsoft.com/VisualStudio/Feedback/Details/2091069
_impl_t() = default;
_impl_t(const _data_t& data) : _data(data)
{
}
_data_t _data;
};
// Base template to be inherited by the statement
template <typename Policies>
struct _base_t
{
using _data_t = no_data_t;
// workaround for msvc bug https://connect.microsoft.com/VisualStudio/Feedback/Details/2091069
template <typename... Args>
_base_t(Args&&... args)
: no_having{std::forward<Args>(args)...}
{
}
_impl_t<Policies> no_having;
_impl_t<Policies>& operator()()
{
return no_having;
}
const _impl_t<Policies>& operator()() const
{
return no_having;
}
template <typename T>
static auto _get_member(T t) -> decltype(t.no_having)
{
return t.no_having;
}
using _database_t = typename Policies::_database_t;
// workaround for msvc bug https://connect.microsoft.com/VisualStudio/Feedback/Details/2173269
// template <typename... T>
// using _check = logic::all_t<is_expression_t<T>::value...>;
template <typename... T>
struct _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_having_t, T>;
using _consistency_check = consistent_t;
template <typename Expression>
auto having(Expression expression) const -> _new_statement_t<_check<Expression>, having_t<void, Expression>>
{
static_assert(_check<Expression>::value, "at least one argument is not an expression in having()");
return _having_impl<void>(_check<Expression>{}, expression);
}
template <typename Expression>
auto dynamic_having(Expression expression) const
-> _new_statement_t<_check<Expression>, having_t<_database_t, Expression>>
{
static_assert(_check<Expression>::value, "at least one argument is not an expression in having()");
static_assert(not std::is_same<_database_t, void>::value,
"dynamic_having must not be called in a static statement");
return _having_impl<_database_t>(_check<Expression>{}, expression);
}
auto dynamic_having() const -> _new_statement_t<_check<boolean_operand>, having_t<_database_t, boolean_operand>>
{
return dynamic_having(::sqlpp::value(true));
}
private:
template <typename Database, typename Expression>
auto _having_impl(const std::false_type&, Expression expression) const -> bad_statement;
template <typename Database, typename Expression>
auto _having_impl(const std::true_type&, Expression expression) const
-> _new_statement_t<std::true_type, having_t<Database, Expression>>
{
return {static_cast<const derived_statement_t<Policies>&>(*this),
having_data_t<Database, Expression>{expression}};
}
};
};
// Interpreters
template <typename Context, typename Database, typename Expression>
struct serializer_t<Context, having_data_t<Database, Expression>>
{
using _serialize_check = serialize_check_of<Context, Expression>;
using T = having_data_t<Database, Expression>;
static Context& _(const T& t, Context& context)
{
context << " HAVING ";
serialize(t._expression, context);
if (not t._dynamic_expressions.empty())
context << " AND ";
interpret_list(t._dynamic_expressions, " AND ", context);
return context;
}
};
}
#endif