DECLARE
DECLARE
creates a cursor, which can be used with
FETCH
, to retrieve a limited number of rows at a time
from a larger query. Large queries or queries that don’t ever complete
(SUBSCRIBE
) can be difficult to use with many PostgreSQL drivers
that wait until all rows are returned before returning control to an
application. Using DECLARE
and FETCH
allows you to
fetch only some of the rows at a time.
Syntax
Field | Use |
---|---|
cursor_name | The name of the cursor to be created. |
query | The query (SELECT or SUBSCRIBE ) that will provide the rows to be returned by the cursor. |