调用存储过程查询年龄小于38的中学生人数：
-- 调用存储过程
mysql> CALL student_procedure(38, @num);
Query OK, 1 row affected
-- 查看返回结果
mysql> select @num;
+------+
| @num |
+------+
| 2 |
+------+
查看存储过程定义
句型：
SHOW CREATE PROCEDURE proc_name;
比如看student_procedure的定义：
mysql> SHOW CREATE PROCEDURE student_procedure;
+-------------------+----------------------------------------------------------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------+----------------------+----------------------+--------------------+
| Procedure | sql_mode | Create Procedure | character_set_client | collation_connection | Database Collation |
+-------------------+----------------------------------------------------------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------+----------------------+----------------------+--------------------+
| student_procedure | STRICT_TRANS_TABLES,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION | CREATE DEFINER=`root`@`localhost` PROCEDURE `student_procedure`(IN age TINYINT, OUT num INT) BEGIN SELECT COUNT(*) INTO num FROM tb_student t WHERE t.age>=age;END | utf8 | utf8_general_ci | utf8_general_ci |
+-------------------+----------------------------------------------------------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------+----------------------+----------------------+--------------------+
