dblink_fetch(text cursorname, int howmany [, bool fail_on_error]) returns setof record dblink_fetch(text connname, text cursorname, int howmany [, bool fail_on_error]) returns setof record
Note: The following description applies only to Postgres-XC
dblink module has not been tested with Postges-XC yet. Although there're no reason that dblink does not run in Postgres-XC, the development team leaves the test and the use of this module entirely to users.
This section is identical to the corresponding PostgreSQL reference manual.
Note: The following description applies only to PostgreSQL
dblink_fetch fetches rows from a cursor previously
established by dblink_open.
Note: The following description applies only to PostgreSQL
Name of the connection to use; omit this parameter to use the unnamed connection.
The name of the cursor to fetch from.
The maximum number of rows to retrieve. The next howmany rows are fetched, starting at the current cursor position, moving forward. Once the cursor has reached its end, no more rows are produced.
If true (the default when omitted) then an error thrown on the remote side of the connection causes an error to also be thrown locally. If false, the remote error is locally reported as a NOTICE, and the function returns no rows.
Note: The following description applies only to PostgreSQL
The function returns the row(s) fetched from the cursor. To use this
function, you will need to specify the expected set of columns,
as previously discussed for dblink.
Note: The following description applies only to PostgreSQL
On a mismatch between the number of return columns specified in the FROM clause, and the actual number of columns returned by the remote cursor, an error will be thrown. In this event, the remote cursor is still advanced by as many rows as it would have been if the error had not occurred. The same is true for any other error occurring in the local query after the remote FETCH has been done.
Note: The following description applies only to PostgreSQL
SELECT dblink_connect('dbname=postgres');
dblink_connect
----------------
OK
(1 row)
SELECT dblink_open('foo', 'select proname, prosrc from pg_proc where proname like ''bytea%''');
dblink_open
-------------
OK
(1 row)
SELECT * FROM dblink_fetch('foo', 5) AS (funcname name, source text);
funcname | source
----------+----------
byteacat | byteacat
byteacmp | byteacmp
byteaeq | byteaeq
byteage | byteage
byteagt | byteagt
(5 rows)
SELECT * FROM dblink_fetch('foo', 5) AS (funcname name, source text);
funcname | source
-----------+-----------
byteain | byteain
byteale | byteale
bytealike | bytealike
bytealt | bytealt
byteane | byteane
(5 rows)
SELECT * FROM dblink_fetch('foo', 5) AS (funcname name, source text);
funcname | source
------------+------------
byteanlike | byteanlike
byteaout | byteaout
(2 rows)
SELECT * FROM dblink_fetch('foo', 5) AS (funcname name, source text);
funcname | source
----------+--------
(0 rows)