On 02/13/2018 11:17 AM, armand pirvu wrote:On Feb 13, 2018, at 12:54 PM, Adrian Klaver <adrian.klaver@xxxxxxxxxxx<mailto:adrian.klaver@xxxxxxxxxxx>> wrote:
On 02/13/2018 10:22 AM, armand pirvu wrote:
Hi
Is there any elegant way not a two steps way I can output the cursor value at each step?
testtbl table has this content
col1 | col2 | col3
------------+------------+------
E1 | CAT1 | 0
E1 | CAT2 | 0
E1 | CAT3 | 0
E4 | CAT1 | 0
E5 | CAT1 | 0
E6 | CAT1 | 0
E7 | CAT1 | 0
This works
BEGIN WORK;
DECLARE fooc CURSOR FOR SELECT * FROM testtbl;
FETCH ALL FROM fooc;
CLOSE fooc;
COMMIT WORK;
col1 | col2 | col3
------------+------------+------
E1 | CAT1 | 0
E1 | CAT2 | 0
E1 | CAT3 | 0
E4 | CAT1 | 0
E5 | CAT1 | 0
E6 | CAT1 | 0
E7 | CAT1 | 0
But
CREATE OR REPLACE FUNCTION foofunc()
RETURNS text AS $$
DECLARE
var2 RECORD;
cur CURSOR FOR SELECT * from testtbl;
BEGIN
OPEN cur;
LOOP
FETCH cur INTO var2;
return var2;
END LOOP;
CLOSE cur;
END; $$
LANGUAGE plpgsql;
CREATE OR REPLACE FUNCTION public.foofunc()
RETURNS SETOF testtbl
LANGUAGE sql
AS $function$
SELECT * FROM testtbl;
$function$
test=> select * from foofunc();
col1 | col2 | col3
------+------+------
E1 | CAT1 | 0
E1 | CAT2 | 0
E1 | CAT3 | 0
E4 | CAT1 | 0
E5 | CAT1 | 0
E6 | CAT1 | 0
E7 | CAT1 | 0
(7 rows)
select foofunc();
foofunc
-------------------------------
("E1 ","CAT1 ",0)
But I am looking to get
foofunc
-------------------------------
("E1 ","CAT1 ",0)
("E1 ","CATs ",0)
etc
Many thanks
— Armand
--
Adrian Klaver
adrian.klaver@xxxxxxxxxxx <mailto:adrian.klaver@xxxxxxxxxxx>
Thanks Adrian
That one I figured it out as well. The idea is that said table has some records which I need to loop and do some processing using cursors similar with
DECLARE
cur CURSOR FOR SELECT *
FROM testtbl FOR UPDATE;
BEGIN
FOR row IN cur LOOP
UPDATE testtbl
SET col3=1
WHERE CURRENT OF cur;
END LOOP;
return cur;
END
For a row update the goal is to return the cursor value be it before/after the update, hence my question and test
Not following, are you looking to do this in an UPDATE trigger or somewhere else?Another way to ask is why do you want to use a cursor?I found some code which seems to do what I need but it involves two functions
CREATE or replace FUNCTION reffunc(refcursor) RETURNS refcursor AS $$
BEGIN
OPEN $1 FOR SELECT col FROM test;
RETURN $1;
END;
$$ LANGUAGE plpgsql;
BEGIN;
SELECT reffunc('funccursor');
FETCH ALL IN funccursor;
COMMIT;
And this is what beats me , aka can I put all in one / how ?
Thanks
Armand
-- Adrian Klaveradrian.klaver@xxxxxxxxxxx
Not a trigger , but the idea is we will do some batch processing from said table let’s name it testtbl
1 - we get the records using select for update with a limit 100 for example
2 - update each record using using cursor
3 - print the cursor content so that way I have an idea what was updated
I was thinking that if I can put a unique constraint on the table, I can generate a global table in the function , update main table from global table and return select from global table
I can see the developer desire to use cursors to minimize some effort on his side
Thanks
Armand
