以下是一个存储过程,它从具有以下数据的表“student_info”的名称列中获取记录 -
mysql> Select * from Student_info; +-----+---------+------------+------------+ | id | Name | Address | Subject | +-----+---------+------------+------------+ | 101 | YashPal | Amritsar | History | | 105 | Gaurav | Chandigarh | Literature | | 125 | Raman | Shimla | Computers | | 127 | Ram | Jhansi | Computers | +-----+---------+------------+------------+ 4 rows in set (0.00 sec) mysql> Delimiter // mysql> CREATE PROCEDURE cursor_defined(OUT val VARCHAR(20)) -> BEGIN -> DECLARE a,b VARCHAR(20); -> DECLARE cur_1 CURSOR for SELECT Name from student_info; -> DECLARE CONTINUE HANDLER FOR NOT FOUND -> SET b = 1; -> OPEN CUR_1; -> REPEAT -> FETCH CUR_1 INTO a; -> UNTIL b = 1 -> END REPEAT; -> CLOSE CUR_1; -> SET val = a; -> END// Query OK, 0 rows affected (0.04 sec) mysql> Delimiter ; mysql> Call cursor_defined2(@val); Query OK, 0 rows affected (0.11 sec) mysql> Select @val; +------+ | @val | +------+ | Ram | +------+ 1 row in set (0.00 sec)
从上面的结果集中,我们可以看到 val 参数的值是“Ram”,因为它是“Name”列的最后一个值。

-----+------------+
4 rows in set (0.00 sec)
mysql> Delimiter //
mysql> CREATE PROCEDURE cursor_defined(OUT val VARCHAR(20))
-> BEGIN
-> DECLARE a,b VARCHAR(20);
-> DECLARE cur_1 CURSOR for SELECT Name from student_info;
-> DECLARE CONTINUE HANDLER FOR NOT FOUND
-> SET b = 1;
-> OPEN CUR_1;
-> REPEAT
-> FETCH CUR_1 INTO a;
-> UNTIL b = 1
-> END REPEAT;
-> CLOSE CUR_1;
-> SET val = a;
-> END//
Query OK, 0 rows affected (0.04 sec)
mysql> Delimiter ;
mysql> Call cursor_defined2(@val);
Query OK, 0 rows affected (0.11 sec)
mysql> Select @val;
+------+
| @val |
+------+
| Ram |
+------+
1 row in set (0.00 sec)






