pqxx::stateless_cursor< up, op > Class Template Reference

"Stateless cursor" class: easy API for retrieving parts of result sets More...

#include <cursor.hxx>

Public Types
using	size_type = result_size_type
using	difference_type = result_difference_type

Public Member Functions
	stateless_cursor (transaction_base &trans, const std::string &query, const std::string &cname, bool hold)
	Create cursor. More...
	stateless_cursor (transaction_base &trans, const std::string adopted_cursor)
	Adopt existing scrolling SQL cursor. More...
void	close () noexcept
size_type	size ()
	Number of rows in cursor's result set. More...
result	retrieve (difference_type begin_pos, difference_type end_pos)
	Retrieve rows from begin_pos (inclusive) to end_pos (exclusive) More...
const std::string &	name () const noexcept

Detailed Description

template<cursor_base::updatepolicy up, cursor_base::ownershippolicy op>
class pqxx::stateless_cursor< up, op >

"Stateless cursor" class: easy API for retrieving parts of result sets

This is a front-end for SQL cursors, but with a more C++-like API.

Actually, stateless_cursor feels entirely different from SQL cursors. You don't keep track of positions, fetches, and moves; you just say which rows you want. See the retrieve() member function.

Member Typedef Documentation

difference_type

template<cursor_base::updatepolicy up, cursor_base::ownershippolicy op>

using pqxx::stateless_cursor< up, op >::difference_type = result_difference_type

size_type

template<cursor_base::updatepolicy up, cursor_base::ownershippolicy op>

using pqxx::stateless_cursor< up, op >::size_type = result_size_type

Constructor & Destructor Documentation

stateless_cursor() [1/2]

template<cursor_base::updatepolicy up, cursor_base::ownershippolicy op>

pqxx::stateless_cursor< up, op >::stateless_cursor	(	transaction_base &	trans,
		const std::string &	query,
		const std::string &	cname,
		bool	hold
	)

Create cursor.

References pqxx::cursor_base::random_access.

stateless_cursor() [2/2]

template<cursor_base::updatepolicy up, cursor_base::ownershippolicy op>

pqxx::stateless_cursor< up, op >::stateless_cursor	(	transaction_base &	trans,
		const std::string	adopted_cursor
	)

Adopt existing scrolling SQL cursor.

References pqxx::cursor_base::backward_all().

Member Function Documentation

close()

template<cursor_base::updatepolicy up, cursor_base::ownershippolicy op>

void pqxx::stateless_cursor< up, op >::close ( )

noexcept

name()

template<cursor_base::updatepolicy up, cursor_base::ownershippolicy op>

const std::string& pqxx::stateless_cursor< up, op >::name ( ) const

noexcept

retrieve()

template<cursor_base::updatepolicy up, cursor_base::ownershippolicy op>

result pqxx::stateless_cursor< up, op >::retrieve	(	difference_type	begin_pos,
		difference_type	end_pos
	)

Retrieve rows from begin_pos (inclusive) to end_pos (exclusive)

Rows are numbered starting from 0 to size()-1.

Parameters

begin_pos	First row to retrieve. May be one row beyond the end of the result set, to avoid errors for empty result sets. Otherwise, must be a valid row number in the result set.
end_pos	Row up to which to fetch. Rows are returned ordered from begin_pos to end_pos, i.e. in ascending order if begin_pos < end_pos but in descending order if begin_pos > end_pos. The end_pos may be arbitrarily inside or outside the result set; only existing rows are included in the result.

size()

template<cursor_base::updatepolicy up, cursor_base::ownershippolicy op>

size_type pqxx::stateless_cursor< up, op >::size

(

)

Number of rows in cursor's result set.

Note

This function is not const; it may need to scroll to find the size of the result set.

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The documentation for this class was generated from the following file:

• cursor.hxx