“字段列表”中的未知列 IN SQL

Question

 DELIMITER //
 CREATE FUNCTION fnc_credit_custstatus
 RETURNS VARCHAR(6) DETERMINISTIC
 BEGIN
 DECLARE custstatus VARCHAR(6);
 IF CustCredit>=1000 THEN SET custstatus='VIP';
 ELSEIF CustCredit<1000 THEN SET custstatus='NONVIP';
 END IF;
 RETURN custstatus;
 END //
 DELIMITER ;

我想我創建 FUNCTION 已經成功，但是當我 SELECT function is Error Code: 1054 Unknown column 'tfield list'

 SELECT*, fnc_credit_custstatus AS custstatus
 FROM customer_salon

Answer 1

你必須傳遞一個參數。這不是語法，因為你沒有定義一個。

drop function if exists f;

DELIMITER //
 CREATE FUNCTION f(custcredit int)
 RETURNS VARCHAR(6) DETERMINISTIC
 BEGIN
 DECLARE custstatus VARCHAR(6);
 IF CustCredit>=1000 THEN SET custstatus='VIP';
 ELSEIF CustCredit<1000 THEN SET custstatus='NONVIP';
 END IF;
 RETURN custstatus;
 END //
 DELIMITER ;
 set @cr = 2000;
 select @cr,f(@cr);

+------+--------+
| @cr  | f(@cr) |
+------+--------+
| 2000 | VIP    |
+------+--------+
1 row in set (0.001 sec)

或者在你的情況下

SELECT *, f(custcredit) AS custstatus FROM customer_salon