Question

我創造了這個觸發：

CREATE TRIGGER trig_update 
AFTER INSERT 
ON "delivery" FOR EACH ROW 
EXECUTE PROCEDURE premium1(); 

有了這個功能：

CREATE OR REPLACE FUNCTION premium1() 
RETURNS trigger AS $$ 
BEGIN 
IF (TG_OP='INSERT') THEN 
IF(select sum(amount) from delivery where cli_num=OLD.cli_num group by cli_num) > 500.00 THEN 
    UPDATE client SET Type ='Gold' WHERE cli_num=OLD.cli_num; 
END IF; 
END IF; 
RETURN NULL; 
END; 
$$LANGUAGE plpgsql; 

當插入表送我提示以下錯誤：一個新的價值：

ERROR: record "old" is not assigned yet Stan SQL:55000

對此有何幫助？

Answer 1

CREATE OR REPLACE FUNCTION premium1() 
RETURNS trigger AS $$ 
BEGIN 
IF (TG_OP='INSERT') THEN 
IF(select sum(amount) from delivery where cli_num=NEW.cli_num group by cli_num) > 500.00 THEN 
    UPDATE client SET Type ='Gold' WHERE cli_num=NEW.cli_num; 
END IF; 
END IF; 
RETURN NULL; 
END; 
$$LANGUAGE plpgsql; 

Answer 2

在AFTER觸發器OLD不可訪問/可見，因爲該記錄還沒有在數據庫中，所以沒有什麼可以比較它。您必須將其更改爲NEW。

從fine manual:

For a row-level trigger, the input data also includes the NEW row for INSERT and UPDATE triggers, and/or the OLD row for UPDATE and DELETE triggers.