MySQL函数 - 错误代码：1415不允许从函数返回结果集

Question

我不想返回结果集，我不知道我在这里做错了什么。 MySQL 5.5

delimiter $$ 

CREATE FUNCTION CheckAccount(
    i_username varchar(50) 
) RETURNS integer 

BEGIN 

    DECLARE v_validUserId int; 
    DECLARE v_validMembership int; 
    DECLARE o_Status integer; 

    SELECT vvalidUserId = u.UserId 
    FROM Users u 
    WHERE u.Username = i_username; 

    IF(v_validUserId IS NULL) THEN 
     SET o_Status = 2; -- Invalid username 
    ELSE 
     SET o_Status = 1; -- Good 
    END IF; 


    IF(o_Status != 2) THEN 
      SELECT v_validMembership = 1 
      FROM Users u 
      JOIN UserMemberships um on um.UserId = u.userId 
      JOIN Memberships m on m.MembershipId = um.MembershipId 
      WHERE um.MembershipExpireDateTime > CURDATE() 
      AND u.UserId = v_validUserId; 

      IF(v_validMembership IS NULL) THEN 
       SET o_Status = 3; -- Invalid membership 
      END IF; 
    END IF; 

    RETURN o_status; 

END $$ 
DELIMITER ; 

任何帮助将不胜感激！

Answer 1

我不确定您是否可以用这种方式分配变量，请尝试使用INTO语句作为您的选择。例如：

SELECT 
    u.UserId INTO vvalidUserId 
FROM 
    Users u 
WHERE 
    u.Username = i_username;