MySQL存儲過程的語句中有三個標准的循環方式：WHILE循環，LOOP循環以及REPEAT循環。還有一種非標准的循環方式：GOTO，不過這種循環方式最好別用，很容易引起程序的混亂，在這裡就不錯具體介紹了。
今天我們先來看看LOOP循環
mysql>
mysql> delimiter $$
mysql>
mysql> CREATE PROCEDURE myProc()
-> BEGIN
->
-> DECLARE i int;
-> SET i=0;
-> loop1: LOOP
-> SET i=i+1;
-> IF i>=10 THEN /*Last number - exit loop*/
-> LEAVE loop1;
-> ELSEIF MOD(i,2)=0 THEN /*Even number - try again*/
-> ITERATE loop1;
-> END IF;
->
-> SELECT CONCAT(i," is an odd number");
->
-> END LOOP loop1;
->
->
-> END$$
Query OK, 0 rows affected (0.02 sec)mysql>
mysql> delimiter ;
mysql> call myProc();
+-------------------------------+
| CONCAT(i," is an odd number") |
+-------------------------------+
| 1 is an odd number |
+-------------------------------+
1 row in set (0.00 sec)+-------------------------------+
| CONCAT(i," is an odd number") |
+-------------------------------+
| 3 is an odd number |
+-------------------------------+
1 row in set (0.00 sec)+-------------------------------+
| CONCAT(i," is an odd number") |
+-------------------------------+
| 5 is an odd number |
+-------------------------------+
1 row in set (0.00 sec)+-------------------------------+
| CONCAT(i," is an odd number") |
+-------------------------------+
| 7 is an odd number |
+-------------------------------+
1 row in set (0.01 sec)+-------------------------------+
| CONCAT(i," is an odd number") |
+-------------------------------+
| 9 is an odd number |
+-------------------------------+
1 row in set (0.01 sec)Query OK, 0 rows affected (0.01 sec)
mysql> drop procedure myProc;
Query OK, 0 rows affected (0.00 sec)mysql>
