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CREATE EXTENSION lo;
CREATE TABLE image (title text, raster lo);
CREATE TRIGGER t_raster BEFORE UPDATE OR DELETE ON image
FOR EACH ROW EXECUTE PROCEDURE lo_manage(raster);
SELECT lo_create(43213);
SELECT lo_create(43214);
INSERT INTO image (title, raster) VALUES ('beautiful image', 43213);
SELECT lo_get(43213);
SELECT lo_get(43214);
UPDATE image SET raster = 43214 WHERE title = 'beautiful image';
SELECT lo_get(43213);
SELECT lo_get(43214);
-- test updating of unrelated column
UPDATE image SET title = 'beautiful picture' WHERE title = 'beautiful image';
SELECT lo_get(43214);
DELETE FROM image;
SELECT lo_get(43214);
-- Now let's try it with an AFTER trigger
DROP TRIGGER t_raster ON image;
CREATE CONSTRAINT TRIGGER t_raster AFTER UPDATE OR DELETE ON image
DEFERRABLE INITIALLY DEFERRED
FOR EACH ROW EXECUTE PROCEDURE lo_manage(raster);
SELECT lo_create(43223);
SELECT lo_create(43224);
SELECT lo_create(43225);
INSERT INTO image (title, raster) VALUES ('beautiful image', 43223);
SELECT lo_get(43223);
UPDATE image SET raster = 43224 WHERE title = 'beautiful image';
SELECT lo_get(43223); -- gone
SELECT lo_get(43224);
-- test updating of unrelated column
UPDATE image SET title = 'beautiful picture' WHERE title = 'beautiful image';
SELECT lo_get(43224);
-- this case used to be buggy
BEGIN;
UPDATE image SET title = 'beautiful image' WHERE title = 'beautiful picture';
UPDATE image SET raster = 43225 WHERE title = 'beautiful image';
SELECT lo_get(43224);
COMMIT;
SELECT lo_get(43224); -- gone
SELECT lo_get(43225);
DELETE FROM image;
SELECT lo_get(43225); -- gone
DROP TABLE image;
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