Question

mysql 存储过程 运行不出来，请高手帮帮忙，mysql5.5

delimiter $$
DROP FUNCTION IF EXISTS sp_login $$
CREATE FUNCTION sp_login( userID VARCHAR(20), passPwd VARCHAR(20)) RETURNS INT(1)
BEGIN
DECLARE flag INT default 5;
IF SELECT Stu1.Authority FROM (SELECT * from Student where Student.StuID = userID and Student.StuPwd = passPwd)Stu1
where Stu1.Authority = '1' > 0 THEN
SET flag = 1;
RETURN flag;
ELSEIF SELECT * from Supervisor where Supervisor.SVID = userID and Supervisor.SVPwd = passPwd > 0 THEN
SET flag = 3;
RETURN flag;
ELSEIF SELECT Stu2.Authority FROM (SELECT * from Student where Student.StuID = userID and Student.StuPwd = passPwd)Stu2
where Stu2.Authority = '2' > 0 THEN
SET flag = 2;
RETURN flag;
ELSEIF SELECT * from Administrator where Administrator.AdminID = userID and Administrator.AdminPwd = passPwd > 0 THEN
SET flag = 0;
RETURN flag;
ELSE
RETURN flag;
END IF;
END $$
delimiter ;
想返回一个整型，用来判断用户登录，执行的时候出错
我想定义一个函数，用来进行用户登录和用户权限判断，有学生、教师、管理员、信息员四种角色（其中信息员是学生的一种角色），这四个角色被存在3张表（Student、Supervisor、Administrator）中，每个表都有用户ID，用户密码和用户权限三个字段，用户权限取值范围为0-3，1代表学生、2代表信息员、3代表老师、0代表管理员，我想在mysql中创建function，接收用户名和密码两个参数，返回一个flag的整型，返回不同的整数，代表不同的角色，现在函数写出来了，但是不能执行，小弟新手，请高手帮忙解决一下，先说声谢啦~~我的mysql版本是5.5,
是无法创建
[Err] 1064 - 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 'SELECT Stu1.Authority FROM (SELECT * from Student where Student.StuID = userID a' at line 4

Answer 1

DROP FUNCTION IF EXISTS sp_login $$
CREATE FUNCTION sp_login( userID VARCHAR(20), passPwd VARCHAR(20)) RETURNS INT(1)
BEGIN
DECLARE flag INT default 5;
DECLARE B BOOLEAN;
SET B=1;
if b then
select count(*) into flag from Student where Student.StuID = userID and Student.StuPwd = passPwd;
if flag then
SELECT Authority into flag FROM Student where Student.StuID = userID and Student.StuPwd = passPwd;
set b=0;
end if;
end if;
if b then
select count(*) into flag from Supervisor where Supervisor.SVID = userID and Supervisor.SVPwd = passPwd;
if flag then
SELECT Authority into flag FROM Supervisor where Supervisor.SVID = userID and Supervisor.SVPwd = passPwd;
set b=0;
end if;
end if;
if b then
select count(*) into flag from Administrator where Administrator.AdminID = userID and Administrator.AdminPwd = passPwd;
if flag then
SELECT Authority into flag FROM Administrator where Administrator.AdminID = userID and Administrator.AdminPwd = passPwd;
set b=0;
end if;
end if;
if b then
return 5;
else
return flag;
end if ;
END $$