ozo::basic_result< T > Class Template Reference

#include <ozo/result.h>

Description

template<typename T>
class ozo::basic_result< T >

Database raw result representation.

This class provides access to the raw representation of a database request result. It models range of rows. Each row can be accessed via index or iterator.

Template Parameters

T	— underlying native result handler type, in common case ozo::pg::result.

Types
using	const_iterator = < implementation defined >
using	iterator = const_iterator

Public Member Functions
const_iterator	begin () const noexcept
const_iterator	end () const noexcept
std::size_t	size () const noexcept
bool	empty () const noexcept
row	operator[] (int i) const noexcept
row	at (int i) const
native_handle_type	native_handle () const noexcept
bool	valid () const noexcept
handle_type	release () noexcept(std::is_nothrow_move_constructible_v< handle_type >)

Types

const_iterator

template<typename T >

using ozo::basic_result< T >::const_iterator = <implementation defined>

Constant iterator on row in the result.

Random access iterator. Provides access to a ozo::row object. Since ozo::basic_result provides read-only access to a database request result, all the iterators provide a read-only access to a ozo::row object.

iterator

template<typename T >

using ozo::basic_result< T >::iterator = const_iterator

Iterator on value in the row, alias on iterator class.

Member Function Documentation

at()

template<typename T >

row ozo::basic_result< T >::at

(

int

i

)

const

Get row by index with range check.

If index in not range [0, size()) throws std::out_of_range.

Parameters

index

— index of a row.

Returns

ozo::row — proxy object to a row.

References ozo::basic_result< T >::size().

begin()

template<typename T >

const_iterator ozo::basic_result< T >::begin ( ) const

noexcept

Iterator on the first row of the result.

Returns

const_iterator — iterator on the first row

References ozo::basic_result< T >::native_handle().

Referenced by ozo::basic_result< T >::end(), and ozo::basic_result< T >::operator[]().

empty()

template<typename T >

bool ozo::basic_result< T >::empty ( ) const

noexcept

Determine whether the result is empty.

Returns

true — no rows in the result, size() == 0, begin() == end().

false — row is not empty, size() > 0, begin() != end().

References ozo::basic_result< T >::size().

end()

template<typename T >

const_iterator ozo::basic_result< T >::end ( ) const

noexcept

Iterator on end of row sequence.

Returns

const_iterator — iterator on end of row sequence

References ozo::basic_result< T >::begin(), and ozo::basic_result< T >::size().

native_handle()

template<typename T >

native_handle_type ozo::basic_result< T >::native_handle ( ) const

noexcept

Get the native libpq handle representation.

This function may be used to obtain the underlying representation of the handle. This is intended to allow access to native handle functionality that is not otherwise provided.

Returns

native_handle_type — native handle representation

Referenced by ozo::basic_result< T >::begin(), and ozo::basic_result< T >::size().

operator[]()

template<typename T >

row ozo::basic_result< T >::operator[] ( int  i ) const

noexcept

Get row by index.

Valid index is in range [0, size()). No index-in-range check is performing.

Note

If given index is out of range the result is UB.

Parameters

index

— index of a row.

Returns

ozo::row — proxy object to a row.

References ozo::basic_result< T >::begin().

release()

template<typename T >

handle_type ozo::basic_result< T >::release ( )

noexcept

Releases ownership of the native connection handle object.

This function may be used to obtain the underlying result handle. After calling this function, valid() returns false.

Returns

handle_type — result handle object

size()

template<typename T >

std::size_t ozo::basic_result< T >::size ( ) const

noexcept

Get count of rows.

Returns

std::size_t — count of rows.

References ozo::basic_result< T >::native_handle().

Referenced by ozo::basic_result< T >::at(), ozo::basic_result< T >::empty(), and ozo::basic_result< T >::end().

valid()

template<typename T >

bool ozo::basic_result< T >::valid ( ) const

noexcept

Checks if object contains result handle.