一个有CASE的过程，总是出错，麻烦看看是咋了

SQL code

DROP PROCEDURE IF EXISTS proc_add_personnel;DELIMITER $$CREATE PROCEDURE proc_add_personnel(ctt INT)BEGIN    DECLARE i INT DEFAULT 0;    DECLARE j INT;    DECLARE pos VARCHAR(10);    SET j = FLOOR(1+(RAND()*6);        CASE j WHEN 1 THEN  pos = '美工';           WHEN 2 THEN  pos = '网页设计';           WHEN 3 THEN  pos = '软件工程师';           WHEN 4 THEN  pos = '架构师';           WHEN 5 THEN  pos = '行政人员';           ELSE pos = '其他';    END CASE        WHILE i<ctt DO     INSERT INTO personnel(`of_year`,`of_position`,`of_wages`) VALUES (FLOOR(1+(RAND()*10)),'',FLOOR(1000+(RAND()*10000)));     SET i= i+1;    END WHILE;END$$

错误信息：

SQL code

Query : create procedure proc_add_personnel(ctt int) begin  declare i int default 0;  declare j int;  DECLARE pos VARCHAR(10);  set j = ...Error Code : 1064You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ';        case j when 1 then  pos = '美工';           WHEN 2 THEN  pos = '网页设?' at line 6

[解决办法]
DROP PROCEDURE IF EXISTS proc_add_personnel;
DELIMITER $$
CREATE PROCEDURE proc_add_personnel(ctt INT)
BEGIN
DECLARE i INT DEFAULT 0;
DECLARE j INT;
DECLARE pos VARCHAR(10);
SET j = FLOOR(1+(RAND()*6);

CASE j WHEN 1 THEN set pos = '美工' ;
WHEN 2 THEN set pos = '网页设计';
WHEN 3 THEN set pos = '软件工程师';
WHEN 4 THEN set pos = '架构师';
WHEN 5 THEN set pos = '行政人员';
ELSE set pos = '其他';
END CASE;

WHILE i<ctt DO
INSERT INTO personnel(`of_year`,`of_position`,`of_wages`) VALUES (FLOOR(1+(RAND()*10)),'',FLOOR(1000+(RAND()*10000)));
SET i= i+1;
END WHILE;
END$$
DELIMITER ;


[解决办法]

SQL code

DROP PROCEDURE IF EXISTS proc_add_personnel;DELIMITER $$CREATE PROCEDURE proc_add_personnel(ctt INT)BEGIN  DECLARE i INT DEFAULT 0;  DECLARE j INT;  DECLARE pos VARCHAR(10);  SET j = FLOOR(1+(RAND()*6));  CASE j WHEN 1 THEN set pos = '美工' ;  WHEN 2 THEN set pos = '网页设计';  WHEN 3 THEN set pos = '软件工程师';  WHEN 4 THEN set pos = '架构师';  WHEN 5 THEN set pos = '行政人员';  ELSE set pos = '其他';  END CASE;     WHILE i<ctt DO  INSERT INTO personnel(`of_year`,`of_position`,`of_wages`) VALUES (FLOOR(1+(RAND()*10)),'',FLOOR(1000+(RAND()*10000)));  SET i= i+1;  END WHILE;END$$DELIMITER ;
[解决办法]
少个分号
[解决办法]
ELIMITER $$
DROP PROCEDURE IF EXISTS proc_add_personnel$$
CREATE PROCEDURE proc_add_personnel(ctt INT)
BEGIN
DECLARE i INT DEFAULT 0;
  DECLARE j INT;
  DECLARE pos VARCHAR(10);
  SET j = FLOOR(1+(RAND()*6));
  CASE j WHEN 1 THEN SET pos='美工';
   WHEN 2 THEN  SET pos = '网页设计';
          WHEN 3 THEN SET pos = '软件工程师';
          WHEN 4 THEN  SET pos = '架构师';
          WHEN 5 THEN SET pos = '行政人员';
          ELSE  SET pos = '其他';
   WHILE i<ctt DO
  INSERT INTO personnel(`of_year`,`of_position`,`of_wages`) VALUES (FLOOR(1+(RAND()*10)),'',FLOOR(1000+(RAND()*10000)));
  SET i= i+1;
  END WHILE;
         
   END CASE;  
      
  
END$$
DELIMITER ;