Provided by: postgresql-client-8.4_8.4.11-1_amd64 bug

NAME

       FETCH - retrieve rows from a query using a cursor

SYNOPSIS

       FETCH [ direction { FROM | IN } ] cursorname

       where direction can be empty or 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 position 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 in
              the documentation.

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 positions 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.

       cursorname
              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 positive 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 intermediate 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 ABSOLUTE 0) is fast.

       DECLARE [declare(7)] is used to define a cursor.  Use  MOVE  [move(7)]  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 extensions.

       The  SQL  standard  allows only FROM preceding the cursor name; the option to use IN is an
       extension.

SEE ALSO

       CLOSE [close(7)], DECLARE [declare(7)], MOVE [move(7)]