mysql ITERATEµÄÒÉÎÊ!!!!

  mysql> CREATE PROCEDURE P20()

    -> BEGIN

    -> DECLARE v INT;

    -> SET v=0;

    -> loop_label: LOOP

    -> IF v=3 THEN

    -> SET v=v+1;

    -> ITERATE loop_label;

    -> END IF;

    -> INSERT INTO t VALUES(v);

    -> SET v = v+1;

    -> IF v>=5 THEN

    -> LEAVE loop_label;

    -> END IF;

    -> END LOOP;

    -> END;//


mysql> select * from t;
+------+
| s1  |
+------+
|    0 |
|    1 |
|    2 |
|    4 |
+------+
4 rows in set (0.00 sec)


  ÔÚÎÒÄÔ×ÓÀïÊÇÕâÑùÔËÐÐµÄ µ±if v=3 ³õʼÊÇ0 ²»µÈÓÚ3 Ö±½ÓÌø³öif  Ö´ÐÐ insert into Ìí¼ÓÒ»ÌõÊý¾ÝΪ0

µÚ¶þ´ÎÖ´ÐÐ v=1 ÁË Ò²²»µÈÓÚÈý ¼ÌÐøÖ´ÐÐ insert Ìí¼ÓÌõÊý¾ÝΪ1  µÚÈý´ÎÖ´ÐÐ v=2 »¹ÊÇÌø³öif Ö´ÐÐinsert Ìí¼ÓÌõÊý¾ÝΪ2

µÚËÄÖ´ÐÐ v=3 ½øÈëifÓï¾äÌå v=3+1 µÈÓÚ4ÁË È»ºóinsert Ò»ÌõÊý¾ÝΪ4  set v =4+1 if 5>=5 Ìø³öÑ­»·£¡£¡£¡


ÎÒµÄÎÊÌâÊÇ ITERATE loop_label; ÕâÌõÓï¾ä ²»ÖªµÀ¸ÉʲôÓÃ!!! ÒÔÉÏÊÇÎÒ×Ô¼ºµÄ·ÖÎö