简单记一下MYSQL里的三种循环：

WHILE,REPEAT,LOOP.

（1）WHILE  contion  DO

执行语句;

          END WHILE;

(2)  REPEAT

执行语句;

UNTIL  countion

END REPEAT;

(3)   pos : LOOP

执行语句;    

IF contion  THEN

LEAVE pos;

END LOOP;

说明：

(1)CREATE PROCEDURE while_test(count int)
BEGIN
 DECLARE i INT;
 SET i = 1;
 WHILE i < count DO
 INSERT INTO xunhuan VALUES(null,'limin');
 SET i = i + 1;
 END WHILE;
END

CALL while_test(20);

(2)CREATE PROCEDURE repeat_test(count INT)
BEGIN 
DECLARE i INT;
SET i =1;
REPEAT
    INSERT into xunhuan values(null,'hah');
 SET i=i+1;
UNTIL i > count
END REPEAT;
END


CALL repeat_test(20);

(3)CREATE PROCEDURE loop_test(count INT)
BEGIN 
DECLARE i INT;
SET i=0;
pos:LOOP
SET i=i+1;
INSERT INTO xunhuan VALUES(null,'lan');
IF i>count THEN
LEAVE pos;
END IF;
END LOOP;
END


call loop_test(20);

除了三种循环外，顺带还把存储过程也说了。