Re: selects possible in VALUES() claueses?
От | Dennis Gearon |
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Тема | Re: selects possible in VALUES() claueses? |
Дата | |
Msg-id | 3E62DE4F.94D1E3D6@cvc.net обсуждение исходный текст |
Ответ на | selects possible in VALUES() claueses? (Dennis Gearon <gearond@cvc.net>) |
Ответы |
Re: selects possible in VALUES() claueses?
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Список | pgsql-general |
I discovered that it's my test trigger on this table that is causing the problem. I've now fixed it, seems the parser needs a set of () around a SELECT statement to allow the value of that statement to be used in another expression. What I've been trying to do is to find out if the NEW value a trigger sees is actually used as part of the database, i.e. is visible to statements inside of the trigger for the NEW INSERT. It seems that they are not. If I've figured this out right, the 'versioning snapshot'is all the data that a trigger will see inside of it, if it's a BEFORE trigger. Will a guru please check my assumptions based on below? This trigger and fuction only allows an INSERT when the number of rows in the table is: GREATER THAN OR EQUAL to 3 BEFORE the INSERT that triggers the FUNCTION. So I see that as proving that the select statement in the function does not see NEW (record) in the Usrs table? -------------------------------------------------------------------- CREATE OR REPLACE FUNCTION test_tgr_on_usrs () RETURNS OPAQUE AS ' DECLARE var_tmp INTEGER; BEGIN var_tmp := (SELECT COUNT(*) FROM Usrs); IF var_tmp < 3 THEN RETURN NULL; ELSE RETURN NEW; END IF; END; ' LANGUAGE 'plpgsql'; CREATE TRIGGER tgr_on_usrs BEFORE INSERT ON Usrs FOR EACH ROW EXECUTE PROCEDURE test_tgr_on_usrs(); Carpe Dancem ;-) ----------------------------------------------------------------- Remember your friends while they are alive ----------------------------------------------------------------- Sincerely, Dennis Gearon
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