如何使用 IN 参数创建 MySQL 存储过程?
为便于理解,我们使用名为“student_info”的表,其中包含以下值 -
mysql> Select * from student_info; +-----+---------+------------+------------+ | id | Name | Address | Subject | +-----+---------+------------+------------+ | 101 | YashPal | Amritsar | History | | 105 | Gaurav | Jaipur | Literature | | 110 | Rahul | Chandigarh | History | | 125 | Raman | Shimla | Computers | +------+--------+------------+------------+ 4 rows in set (0.00 sec)
现在,在以下查询的帮助下,我们将使用 IN 参数创建存储过程,该过程将通过提供作为参数的名称来显示特定学生的所有详细信息。
mysql> DELIMITER // ; mysql> Create PROCEDURE detail(IN S_Name VARCHAR(20)) -> BEGIN -> SELECT * From Student_info WHERE Name = S_Name; -> END // Query OK, 0 rows affected (0.16 sec) mysql> DELIMITER ;
S_Name 是存储过程“detail”的 IN 参数。如果我们想查看学生姓名为“Gaurav”的所有详细信息,则可以使用以下查询来完成 -
mysql> CALL detail('Gaurav'); +-----+--------+---------+------------+ | id | Name | Address | Subject | +-----+--------+---------+------------+ | 105 | Gaurav | Jaipur | Literature | +-----+--------+---------+------------+ 1 row in set (0.00 sec) Query OK, 0 rows affected (0.01 sec) mysql> CALL detail('Raman'); +-----+-------+---------+-----------+ | id | Name | Address | Subject | +-----+-------+---------+-----------+ | 125 | Raman | Shimla | Computers | +-----+-------+---------+-----------+ 1 row in set (0.00 sec) Query OK, 0 rows affected (0.01 sec)
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