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FETCH(7)		  PostgreSQL 18.4 Documentation 		FETCH(7)

NAME
     FETCH - retrieve rows from a query using a cursor

SYNOPSIS
     FETCH [ direction ] [ FROM | IN ] cursor_name

     where direction can be one of:

	 NEXT
	 PRIOR
	 FIRST
	 LAST
	 ABSOLUTE count
	 RELATIVE count
	 count
	 ALL
	 FORWARD
	 FORWARD count
	 FORWARD ALL
	 BACKWARD
	 BACKWARD count
	 BACKWARD ALL

DESCRIPTION
     FETCH retrieves rows using a previously-created cursor.

     A cursor has an associated position, which is used by FETCH. The cursor po-
     sition  can  be before the first row of the query result, on any particular
     row of the result, or after the last row of the  result.  When  created,  a
     cursor  is  positioned  before the first row. After fetching some rows, the
     cursor is positioned on the row most recently retrieved. If FETCH runs  off
     the  end of the available rows then the cursor is left positioned after the
     last row, or before the first row if fetching backward.  FETCH ALL or FETCH
     BACKWARD ALL will always leave the cursor positioned after the last row  or
     before the first row.

     The  forms  NEXT, PRIOR, FIRST, LAST, ABSOLUTE, RELATIVE fetch a single row
     after moving the cursor appropriately. If there is no such  row,  an  empty
     result  is returned, and the cursor is left positioned before the first row
     or after the last row as appropriate.

     The forms using FORWARD and BACKWARD retrieve the indicated number of  rows
     moving  in the forward or backward direction, leaving the cursor positioned
     on the last-returned row (or after/before all rows, if  the  count  exceeds
     the number of rows available).

     RELATIVE  0, FORWARD 0, and BACKWARD 0 all request fetching the current row
     without moving the cursor, that is, re-fetching the most  recently  fetched
     row. This will succeed unless the cursor is positioned before the first row
     or after the last row; in which case, no row is returned.

	 Note

	 This  page  describes usage of cursors at the SQL command level. If you
	 are trying to use cursors inside a PL/pgSQL  function,  the  rules  are
	 different -- see Section 41.7.3.

PARAMETERS
     direction
	 direction  defines  the fetch direction and number of rows to fetch. It
	 can be one of the following:

	 NEXT
	     Fetch the next row. This is the default if direction is omitted.

	 PRIOR
	     Fetch the prior row.

	 FIRST
	     Fetch the first row of the query (same as ABSOLUTE 1).

	 LAST
	     Fetch the last row of the query (same as ABSOLUTE -1).

	 ABSOLUTE count
	     Fetch the count'th row of the query, or the abs(count)'th row  from
	     the  end  if  count is negative. Position before first row or after
	     last row if count is out of range; in particular, ABSOLUTE 0  posi-
	     tions before the first row.

	 RELATIVE count
	     Fetch  the  count'th succeeding row, or the abs(count)'th prior row
	     if count is negative.  RELATIVE 0 re-fetches the  current	row,  if
	     any.

	 count
	     Fetch the next count rows (same as FORWARD count).

	 ALL
	     Fetch all remaining rows (same as FORWARD ALL).

	 FORWARD
	     Fetch the next row (same as NEXT).

	 FORWARD count
	     Fetch the next count rows.  FORWARD 0 re-fetches the current row.

	 FORWARD ALL
	     Fetch all remaining rows.

	 BACKWARD
	     Fetch the prior row (same as PRIOR).

	 BACKWARD count
	     Fetch  the  prior	count  rows  (scanning	backwards).   BACKWARD 0
	     re-fetches the current row.

	 BACKWARD ALL
	     Fetch all prior rows (scanning backwards).

     count
	 count is a possibly-signed integer constant, determining  the	location
	 or  number of rows to fetch. For FORWARD and BACKWARD cases, specifying
	 a negative count is equivalent to changing the  sense	of  FORWARD  and
	 BACKWARD.

     cursor_name
	 An open cursor's name.

OUTPUTS
     On successful completion, a FETCH command returns a command tag of the form

	 FETCH count

     The count is the number of rows fetched (possibly zero). Note that in psql,
     the  command  tag	will  not actually be displayed, since psql displays the
     fetched rows instead.

NOTES
     The cursor should be declared with the SCROLL option if one intends to  use
     any  variants  of FETCH other than FETCH NEXT or FETCH FORWARD with a posi-
     tive count. For simple queries PostgreSQL will allow backwards  fetch  from
     cursors  not declared with SCROLL, but this behavior is best not relied on.
     If the cursor is declared with NO SCROLL, no backward fetches are allowed.

     ABSOLUTE fetches are not any faster than navigating to the desired row with
     a relative move: the underlying implementation must traverse all the inter-
     mediate rows anyway. Negative absolute fetches are even  worse:  the  query
     must  be  read to the end to find the last row, and then traversed backward
     from there. However, rewinding to the start of the query (as with FETCH AB-
     SOLUTE 0) is fast.

     DECLARE is used to define a cursor. Use  MOVE  to	change	cursor	position
     without retrieving data.

EXAMPLES
     The following example traverses a table using a cursor:

	 BEGIN WORK;

	 -- Set up a cursor:
	 DECLARE liahona SCROLL CURSOR FOR SELECT * FROM films;

	 -- Fetch the first 5 rows in the cursor liahona:
	 FETCH FORWARD 5 FROM liahona;

	  code	|	   title	  | did | date_prod  |	 kind	|  len
	 -------+-------------------------+-----+------------+----------+-------
	  BL101 | The Third Man 	  | 101 | 1949-12-23 | Drama	| 01:44
	  BL102 | The African Queen	  | 101 | 1951-08-11 | Romantic | 01:43
	  JL201 | Une Femme est une Femme | 102 | 1961-03-12 | Romantic | 01:25
	  P_301 | Vertigo		  | 103 | 1958-11-14 | Action	| 02:08
	  P_302 | Becket		  | 103 | 1964-02-03 | Drama	| 02:28

	 -- Fetch the previous row:
	 FETCH PRIOR FROM liahona;

	  code	|  title  | did | date_prod  |	kind  |  len
	 -------+---------+-----+------------+--------+-------
	  P_301 | Vertigo | 103 | 1958-11-14 | Action | 02:08

	 -- Close the cursor and end the transaction:
	 CLOSE liahona;
	 COMMIT WORK;

COMPATIBILITY
     The SQL standard defines FETCH for use in embedded SQL only. The variant of
     FETCH  described here returns the data as if it were a SELECT result rather
     than placing it in host variables. Other than this point,	FETCH  is  fully
     upward-compatible with the SQL standard.

     The  FETCH forms involving FORWARD and BACKWARD, as well as the forms FETCH
     count and FETCH ALL, in which FORWARD is implicit,  are  PostgreSQL  exten-
     sions.

     The  SQL standard allows only FROM preceding the cursor name; the option to
     use IN, or to leave them out altogether, is an extension.

SEE ALSO
     CLOSE(7), DECLARE(7), MOVE(7)

PostgreSQL 18.4 		      2026				FETCH(7)

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