MySQL存储函数问题

Question

我正在创建这样的存储函数

CREATE FUNCTION getVendorID(IN venname VARCHAR(255)) 
RETURNS INT
BEGIN
    DECLARE a INT;
    SELECT vendorid FROM vendors WHERE vendorname LIKE venname INTO a;
    RETURN a;
END$$

但我收到一个错误:

ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'IN venname VARCHAR(255))
RETURNS INT
BEGIN
DECLARE a INT;
SELECT vendorid FRO' at line 1

Answer 1

MySQL 函数只接受 IN 参数，因此它们不能声明为 IN。

DELIMITER $$
CREATE FUNCTION getVendorID(venname VARCHAR(255)) 
RETURNS INT
BEGIN
    DECLARE a INT;
    SELECT vendorid INTO a FROM vendors WHERE vendorname LIKE venname;
    RETURN a;
END$$
DELIMITER ;