2011-02-01 131 views
14

我:PostgreSQL触发错误

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OLDNEW。我该如何解决这个问题?

回答

18

您需要使用FOR EACH ROW

CREATE TRIGGER triggerPodan AFTER INSERT OR DELETE 
ON "Podania" FOR EACH ROW 
EXECUTE PROCEDURE aktualizujIloscPodan(); 
12

对于delete只触发OLD记录被定义并且NEW未定义。因此,在代码中,检查触发器是否运行为DELETEINSERT(变量TG_OP)并访问相应的记录。

此外,你可以去没有在这里所有的清点,像这样:

CREATE OR REPLACE FUNCTION aktualizujIloscPodan() RETURNS TRIGGER AS 
$BODY$ 
DECLARE 
    n integer; 
BEGIN 
    IF TG_OP = 'INSERT' then 
     UPDATE "Studenci" SET "ilosc_podan" = "ilosc_podan" + 1 WHERE "ID"=NEW."studentID"; 
    ELSIF TG_OP = 'DELETE' then 
     UPDATE "Studenci" SET "ilosc_podan" = "ilosc_podan" - 1 WHERE "ID"=OLD."studentID"; 

    END IF; 
END; 

$BODY$ 
LANGUAGE plpgsql; 

DROP TRIGGER IF EXISTS triggenPodan ON "Podania"; 

CREATE TRIGGER triggenPodan AFTER INSERT OR DELETE 
ON "Podania" 
EXECUTE PROCEDURE aktualizujIloscPodan(); 
+0

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

+0

@Miko抱歉,我没有检查它。编辑。 – 2011-02-01 22:13:20