pqxx::internal::sql_cursor Class Reference

Cursor with SQL positioning semantics. More...

#include <cursor.hxx>

Inheritance diagram for pqxx::internal::sql_cursor:

Public Member Functions
	sql_cursor (transaction_base &t, const std::string &query, const std::string &cname, cursor_base::accesspolicy ap, cursor_base::updatepolicy up, cursor_base::ownershippolicy op, bool hold)
	sql_cursor (transaction_base &t, const std::string &cname, cursor_base::ownershippolicy op)
	~sql_cursor () noexcept
result	fetch (difference_type rows, difference_type &displacement)
result	fetch (difference_type rows)
difference_type	move (difference_type rows, difference_type &displacement)
difference_type	move (difference_type rows)
difference_type	pos () const noexcept
	Current position, or -1 for unknown. More...
difference_type	endpos () const noexcept
	End position, or -1 for unknown. More...
const result &	empty_result () const noexcept
	Return zero-row result for this cursor. More...
void	close () noexcept
Public Member Functions inherited from pqxx::cursor_base
	cursor_base ()=delete
	cursor_base (const cursor_base &)=delete
cursor_base &	operator= (const cursor_base &)=delete
const std::string &	name () const noexcept
	Name of underlying SQL cursor. More...

Additional Inherited Members
Public Types inherited from pqxx::cursor_base
enum	accesspolicy { forward_only, random_access }
	Cursor access-pattern policy. More...
enum	updatepolicy { read_only, update }
	Cursor update policy. More...
enum	ownershippolicy { owned, loose }
	Cursor destruction policy. More...
using	size_type = result_size_type
using	difference_type = result_difference_type
Static Public Member Functions inherited from pqxx::cursor_base
static difference_type	all () noexcept
	Special value: read until end. More...
static difference_type	next () noexcept
	Special value: read one row only. More...
static difference_type	prior () noexcept
	Special value: read backwards, one row only. More...
static difference_type	backward_all () noexcept
	Special value: read backwards from current position back to origin. More...
Protected Member Functions inherited from pqxx::cursor_base
	cursor_base (connection_base &, const std::string &Name, bool embellish_name=true)
Protected Attributes inherited from pqxx::cursor_base
const std::string	m_name

Detailed Description

Cursor with SQL positioning semantics.

Thin wrapper around an SQL cursor, with SQL's ideas of positioning.

SQL cursors have pre-increment/pre-decrement semantics, with on either end of the result set a special position that does not repesent a row. This class models SQL cursors for the purpose of implementing more C++-like semantics on top.

Positions of actual rows are numbered starting at 1. Position 0 exists but does not refer to a row. There is a similar non-row position at the end of the result set.

Don't use this at home. You deserve better. Use the stateles_cursor instead.

Constructor & Destructor Documentation

sql_cursor() [1/2]

pqxx::internal::sql_cursor::sql_cursor	(	transaction_base &	t,
		const std::string &	query,
		const std::string &	cname,
		cursor_base::accesspolicy	ap,
		cursor_base::updatepolicy	up,
		cursor_base::ownershippolicy	op,
		bool	hold
	)

References pqxx::connection_base::activate(), pqxx::transaction_base::conn(), pqxx::transaction_base::exec(), pqxx::cursor_base::forward_only, pqxx::cursor_base::name(), and pqxx::cursor_base::update.

sql_cursor() [2/2]

pqxx::internal::sql_cursor::sql_cursor	(	transaction_base &	t,
		const std::string &	cname,
		cursor_base::ownershippolicy	op
	)

References pqxx::transaction_base::conn(), and pqxx::cursor_base::owned.

~sql_cursor()

pqxx::internal::sql_cursor::~sql_cursor ( )

noexcept

Member Function Documentation

close()

void pqxx::internal::sql_cursor::close ( )

noexcept

References pqxx::result::affected_rows(), pqxx::cursor_base::all(), pqxx::cursor_base::backward_all(), pqxx::transaction_base::exec(), fetch(), pqxx::cursor_base::loose, move(), pqxx::cursor_base::name(), pqxx::cursor_base::owned, pos(), pqxx::result::size(), and pqxx::to_string().

empty_result()

const result& pqxx::internal::sql_cursor::empty_result ( ) const

noexcept

Return zero-row result for this cursor.

References pqxx::internal::obtain_stateless_cursor_size(), and pqxx::internal::stateless_cursor_retrieve().

Referenced by pqxx::internal::stateless_cursor_retrieve().

endpos()

difference_type pqxx::internal::sql_cursor::endpos ( ) const

noexcept

End position, or -1 for unknown.

Returns the final position, just after the last row in the result set. The starting position, just before the first row, counts as position zero.

End position is unknown until it is encountered during use.

Referenced by pqxx::internal::obtain_stateless_cursor_size().

fetch() [1/2]

result pqxx::internal::sql_cursor::fetch	(	difference_type	rows,
		difference_type &	displacement
	)

Referenced by close(), pqxx::icursorstream::set_stride(), and pqxx::internal::stateless_cursor_retrieve().

fetch() [2/2]

result pqxx::internal::sql_cursor::fetch

(

difference_type

rows

)

move() [1/2]

difference_type pqxx::internal::sql_cursor::move	(	difference_type	rows,
		difference_type &	displacement
	)

Referenced by close(), pqxx::icursorstream::ignore(), pqxx::internal::obtain_stateless_cursor_size(), and pqxx::internal::stateless_cursor_retrieve().

move() [2/2]

difference_type pqxx::internal::sql_cursor::move

(

difference_type

rows

)

pos()

difference_type pqxx::internal::sql_cursor::pos ( ) const

noexcept

Current position, or -1 for unknown.

The starting position, just before the first row, counts as position zero.

Position may be unknown if (and only if) this cursor was adopted, and has never hit its starting position (position zero).

Referenced by close(), and pqxx::internal::stateless_cursor_retrieve().

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

• cursor.hxx
• cursor.cxx