Question

我创造了这个触发：

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

有了这个功能：

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; 

当插入表送我提示以下错误：一个新的价值：

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

对此有何帮助？

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触发器OLD不可访问/可见，因为该记录还没有在数据库中，所以没有什么可以比较它。您必须将其更改为NEW。

从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.