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#ifndef DB_SELECTCOMMANDUTIL_IMPL_H
#define DB_SELECTCOMMANDUTIL_IMPL_H
#include "selectcommand.h"
#include <type_traits>
/// @cond
namespace DB {
template<typename Fields, typename Func, unsigned int field, typename ... Fn, typename ... Args>
inline void
forEachField(DB::SelectCommand * sel, const Func & func, const Args & ... args)
{
if constexpr (field >= std::tuple_size<Fields>::value) {
(void)sel;
func(args...);
}
else {
typename std::tuple_element<field, Fields>::type a;
(*sel)[field] >> a;
forEachField<Fields, Func, field + 1, Fn...>(sel, func, args..., a);
}
}
template<typename ... Fn, typename Func>
inline void SelectCommand::forEachRow(const Func & func)
{
while (fetch()) {
forEachField<std::tuple<Fn...>, Func, 0>(this, func);
}
}
template<typename ... Fn>
inline RowRange<Fn...> SelectCommand::as()
{
return RowRange<Fn...>(this);
}
template<typename ... Fn>
inline RowRange<Fn...>::RowRange(SelectCommand * s) :
sel(s)
{
}
template<typename ... Fn>
inline RowRangeIterator<Fn...> RowRange<Fn...>::begin() const
{
return RowRangeIterator<Fn...>(sel);
}
template<typename ... Fn>
inline RowRangeIterator<Fn...> RowRange<Fn...>::end() const
{
return RowRangeIterator<Fn...>(nullptr);
}
template<typename ... Fn>
inline RowRangeIterator<Fn...>::RowRangeIterator(SelectCommand * s) :
sel(s)
{
if (sel) {
validRow = sel->fetch();
}
else {
validRow = false;
}
}
template<typename ... Fn>
inline bool RowRangeIterator<Fn...>::operator!=(const RowRangeIterator &) const
{
return validRow;
}
template<typename ... Fn>
inline void RowRangeIterator<Fn...>::operator++()
{
validRow = sel->fetch();
}
template<typename ... Fn>
inline Row<Fn...> RowRangeIterator<Fn...>::operator*() const
{
return Row<Fn...>(sel);
}
template<typename ... Fn>
inline Row<Fn...>::Row(SelectCommand * s) :
RowBase(s)
{
}
template<typename ... Fn>
template<unsigned int C>
inline typename std::tuple_element<C, std::tuple<Fn...>>::type Row<Fn...>::value() const
{
typename std::tuple_element<C, std::tuple<Fn...>>::type a;
sel->operator[](C) >> a;
return a;
}
}
/// @endcond
#endif
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