mysql - 这个mysql语法有什么错误？

Question

我是 mysql 世界的新手。我正在尝试创建一个程序来根据他/她的 GPA 来决定学生的类(class)。我给了他们一个 CRegNo，它当时是 1 到 10。这是我的代码:

mysql> delimiter //
 mysql> CREATE PROCEDURE DecideClass ()
    -> BEGIN
    -> DECLARE count INT;
    -> DECLARE max INT;
    -> SET count = 1;
    -> SET max = 10;
    -> DECLARE FClass CHAR(18) DEFAULT 'First class honors';
    -> DECLARE sUpper CHAR(34) DEFAULT 'Second class honors-upper division';
    -> DECLARE sLower CHAR(34) DEFAULT 'Second class honors-lower division';
    -> DECLARE tClass CHAR(18) DEFAULT 'Third class honors';
    -> WHILE count <= max DO
    -> DECLARE GPA DECIMAL(3,2);
    -> SET GPA = (SELECT GPA FROM STUDENT WHERE CRegNo = count);
    -> IF GPA >= 3.7 THEN
    -> UPDATE STUDENT SET Class = FClass WHERE CRegNo = count;
    -> ELSE IF GPA < 3.7 AND GPA >= 3.3 THEN
    -> UPDATE STUDENT SET Class = SUpper WHERE CRegNo = count;
    -> ELSE IF GPA < 3.3 AND GPA >= 2.7 THEN
    -> UPDATE STUDENT SET Class = SLower WHERE CRegNo = count;
    -> ELSE IF GPA < 2.7 AND GPA >= 2.0 THEN
    -> UPDATE STUDENT SET Class = TClass WHERE CRegNo = count;
    -> END IF
    -> SET count = count + 1;
    -> END WHILE;
    -> END;
    -> //

然后它说

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 'DECLARE FClass CHAR(18) DEFAULT 'First class honors'; DECLARE sUpper CHAR(34) DE' at line 7

有人可以帮我吗？错误是什么？

Answer 1

所有的 DECLARE 语句都必须在开头，在任何 SET 或任何其他内容之前。