14
CREATE OR REPLACE FUNCTION aktualizujIloscPodan() RETURNS TRIGGER AS
$BODY$
DECLARE
n integer;
sid integer;
BEGIN
sid=0;
IF (TG_OP='INSERT') THEN
sid = NEW."studentID";
ELSIF (TG_OP='DELETE') THEN
sid = OLD."studentID";
END IF;
n = COALESCE ((SELECT count("studentID") as c
FROM "Podania" WHERE "studentID"=sid
GROUP BY "studentID"), 0);
UPDATE "Studenci" SET "licznikpodan" = n WHERE "ID"=sid;
END;
$BODY$
LANGUAGE plpgsql;
DROP TRIGGER IF EXISTS triggenPodan ON "Podania";
CREATE TRIGGER triggenPodan AFTER INSERT OR DELETE
ON "Podania"
EXECUTE PROCEDURE aktualizujIloscPodan();
当我尝试执行:
DELETE FROM "Podania"
I get
ERROR: record "old" is not assigned yet
DETAIL: The tuple structure of a not-yet-assigned record is indeterminate.
CONTEXT: PL/pgSQL function "aktualizujiloscpodan" line 11 at assignment
********** Błąd **********
ERROR: record "old" is not assigned yet
Stan SQL:55000
Szczegóły:The tuple structure of a not-yet-assigned record is indeterminate.
Kontekst:PL/pgSQL function "aktualizujiloscpodan" line 11 at assignment
现在看来似乎不知道什么是OLD
或NEW
。我该如何解决这个问题?
好吧,也许我并不需要统计...修改我的代码,并有另一个错误。你能帮我吗?有两件事:它不允许返回NULL(无返回工作),它是`ELSIF`而不是`ELIF` – 2011-02-01 22:02:33
@Miko抱歉,我没有检查它。编辑。 – 2011-02-01 22:13:20