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sqlpp11/include/sqlpp11/integral.h
2014-07-28 07:41:59 +02:00

317 lines
8.9 KiB
C++

/*
* Copyright (c) 2013-2014, 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_INTEGRAL_H
#define SQLPP_INTEGRAL_H
#include <cstdlib>
#include <sqlpp11/basic_expression_operators.h>
#include <sqlpp11/type_traits.h>
#include <sqlpp11/exception.h>
#include <sqlpp11/value_type.h>
#include <sqlpp11/assignment.h>
namespace sqlpp
{
namespace detail
{
// integral value type
struct integral
{
using _traits = make_traits<integral, ::sqlpp::tag::is_integral, ::sqlpp::tag::is_expression>;
using _tag = ::sqlpp::tag::is_integral;
using _cpp_value_type = int64_t;
struct _parameter_t
{
using _value_type = integral;
_parameter_t():
_value(0),
_is_null(true)
{}
explicit _parameter_t(const _cpp_value_type& value):
_value(value),
_is_null(false)
{}
_parameter_t& operator=(const _cpp_value_type& value)
{
_value = value;
_is_null = false;
return *this;
}
void set_null()
{
_value = 0;
_is_null = true;
}
bool is_null() const
{
return _is_null;
}
const _cpp_value_type& value() const
{
return _value;
}
operator _cpp_value_type() const { return _value; }
template<typename Target>
void _bind(Target& target, size_t index) const
{
target._bind_integral_parameter(index, &_value, _is_null);
}
private:
_cpp_value_type _value;
bool _is_null;
};
template<typename Db, typename FieldSpec>
struct _result_field_t;
// I am SO waiting for concepts lite!
template<typename Field, typename Enable = void>
struct field_methods_t
{
static constexpr bool _null_is_trivial = true;
operator _cpp_value_type() const { return static_cast<const Field&>(*this).value(); }
};
template<typename Db, typename FieldSpec>
struct field_methods_t<
_result_field_t<Db, FieldSpec>,
typename std::enable_if<enforce_null_result_treatment_t<Db>::value
and column_spec_can_be_null_t<FieldSpec>::value
and not null_is_trivial_value_t<FieldSpec>::value>::type>
{
static constexpr bool _null_is_trivial = false;
};
template<typename Db, typename FieldSpec>
struct _result_field_t: public field_methods_t<_result_field_t<Db, FieldSpec>>
{
using _field_methods_t = field_methods_t<_result_field_t<Db, FieldSpec>>;
using _traits = make_traits<integral,
tag_if<tag::null_is_trivial_value, _field_methods_t::_null_is_trivial>>;
struct _recursive_traits
{
using _parameters = std::tuple<>;
using _provided_tables = detail::type_set<>;
using _provided_outer_tables = detail::type_set<>;
using _required_tables = detail::type_set<>;
using _extra_tables = detail::type_set<>;
using _can_be_null = column_spec_can_be_null_t<FieldSpec>;
};
_result_field_t():
_is_valid(false),
_is_null(true),
_value(0)
{}
void _invalidate()
{
_is_valid = false;
_is_null = true;
_value = 0;
}
void _validate()
{
_is_valid = true;
}
bool is_null() const
{
if (not _is_valid)
throw exception("accessing is_null in non-existing row");
return _is_null;
}
_cpp_value_type value() const
{
if (not _is_valid)
throw exception("accessing value in non-existing row");
if (_is_null)
{
if (enforce_null_result_treatment_t<Db>::value and not null_is_trivial_value_t<FieldSpec>::value)
{
throw exception("accessing value of NULL field");
}
else
{
return 0;
}
}
return _value;
}
template<typename Target>
void _bind(Target& target, size_t i)
{
target._bind_integral_result(i, &_value, &_is_null);
}
private:
bool _is_valid;
bool _is_null;
_cpp_value_type _value;
};
template<typename T>
struct _is_valid_operand
{
static constexpr bool value =
is_expression_t<T>::value // expressions are OK
and is_numeric_t<T>::value // the correct value type is required, of course
;
};
template<typename Base>
struct expression_operators: public basic_expression_operators<Base, is_numeric_t>
{
template<typename T>
plus_t<Base, value_type_t<T>, wrap_operand_t<T>> operator +(T t) const
{
using rhs = wrap_operand_t<T>;
static_assert(_is_valid_operand<rhs>::value, "invalid rhs operand");
return { *static_cast<const Base*>(this), {t} };
}
template<typename T>
minus_t<Base, value_type_t<T>, wrap_operand_t<T>> operator -(T t) const
{
using rhs = wrap_operand_t<T>;
static_assert(_is_valid_operand<rhs>::value, "invalid rhs operand");
return { *static_cast<const Base*>(this), {t} };
}
template<typename T>
multiplies_t<Base, value_type_t<T>, wrap_operand_t<T>> operator *(T t) const
{
using rhs = wrap_operand_t<T>;
static_assert(_is_valid_operand<rhs>::value, "invalid rhs operand");
return { *static_cast<const Base*>(this), {t} };
}
template<typename T>
divides_t<Base, wrap_operand_t<T>> operator /(T t) const
{
using rhs = wrap_operand_t<T>;
static_assert(_is_valid_operand<rhs>::value, "invalid rhs operand");
return { *static_cast<const Base*>(this), {t} };
}
template<typename T>
modulus_t<Base, wrap_operand_t<T>> operator %(T t) const
{
using rhs = wrap_operand_t<T>;
static_assert(_is_valid_operand<rhs>::value, "invalid rhs operand");
return { *static_cast<const Base*>(this), {t} };
}
unary_plus_t<integral, Base> operator +() const
{
return { *static_cast<const Base*>(this) };
}
unary_minus_t<integral, Base> operator -() const
{
return { *static_cast<const Base*>(this) };
}
};
template<typename Base>
struct column_operators
{
template<typename T>
auto operator +=(T t) const -> assignment_t<Base, plus_t<Base, value_type_t<T>, wrap_operand_t<T>>>
{
using rhs = wrap_operand_t<T>;
static_assert(_is_valid_operand<rhs>::value, "invalid rhs assignment operand");
return { *static_cast<const Base*>(this), { *static_cast<const Base*>(this), rhs{t} } };
}
template<typename T>
auto operator -=(T t) const -> assignment_t<Base, minus_t<Base, value_type_t<T>, wrap_operand_t<T>>>
{
using rhs = wrap_operand_t<T>;
static_assert(_is_valid_operand<rhs>::value, "invalid rhs assignment operand");
return { *static_cast<const Base*>(this), { *static_cast<const Base*>(this), rhs{t} } };
}
template<typename T>
auto operator /=(T t) const -> assignment_t<Base, divides_t<Base, wrap_operand_t<T>>>
{
using rhs = wrap_operand_t<T>;
static_assert(_is_valid_operand<rhs>::value, "invalid rhs assignment operand");
return { *static_cast<const Base*>(this), { *static_cast<const Base*>(this), rhs{t} } };
}
template<typename T>
auto operator *=(T t) const -> assignment_t<Base, multiplies_t<Base, value_type_t<T>, wrap_operand_t<T>>>
{
using rhs = wrap_operand_t<T>;
static_assert(_is_valid_operand<rhs>::value, "invalid rhs assignment operand");
return { *static_cast<const Base*>(this), { *static_cast<const Base*>(this), rhs{t} } };
}
};
};
template<typename Db, typename FieldSpec>
inline std::ostream& operator<<(std::ostream& os, const integral::_result_field_t<Db, FieldSpec>& e)
{
return os << e.value();
}
}
using tinyint = detail::integral;
using smallint = detail::integral;
using integer = detail::integral;
using bigint = detail::integral;
}
#endif