MySQL使用分隔符创建存储过程语法

Question

我试图在MySQL中使用这样的分隔符创建一个存储过程:

use am;

DELIMITER $$

CREATE PROCEDURE addfields()
BEGIN
  DECLARE done INT DEFAULT FALSE;
  DECLARE acc INT(16);
  DECLARE validId INT DEFAULT 0;

END $$

DELIMITER ;

它给了我一个错误:

#1304 - PROCEDURE addfields already exists

使用分隔符创建存储过程并在首先存在时删除它的正确语法是什么？

Answer 1

在MySQL中开始使用存储过程语法:

优秀的程序员使用终端,GUI让你在中间变得柔软.当你习惯它并记住命令时,它比任何GUI快5倍.生产力=成功.

1.打开终端并登录mysql,如下所示:

el@apollo:~$ mysql -u root -p
Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or \g.
mysql> 

2.看看你是否有任何程序:

mysql> show procedure status;
+-----------+---------------+-----------+---------+---------------------+---------------------+---------------+---------+----------------------+----------------------+--------------------+
| Db        | Name          | Type      | Definer | Modified            | Created             | Security_type | Comment | character_set_client | collation_connection | Database Collation |
+-----------+---------------+-----------+---------+---------------------+---------------------+---------------+---------+----------------------+----------------------+--------------------+
|   yourdb  | sp_user_login | PROCEDURE | root@%  | 2013-12-06 14:10:25 | 2013-12-06 14:10:25 | DEFINER       |         | utf8                 | utf8_general_ci      | latin1_swedish_ci  |
+-----------+---------------+-----------+---------+---------------------+---------------------+---------------+---------+----------------------+----------------------+--------------------+
1 row in set (0.01 sec)

我有一个定义,你可能没有开始.

3.切换到数据库,删除它.

mysql> use yourdb;
Database changed

mysql> drop procedure if exists sp_user_login;
Query OK, 0 rows affected (0.01 sec)

mysql> show procedure status;
Empty set (0.00 sec)

好的,现在我没有定义存储过程.做最简单的一个:

mysql> delimiter //
mysql> create procedure foobar()
    -> begin select 'hello'; end//
Query OK, 0 rows affected (0.00 sec)

完成输入存储过程的命令后,//将与终端通信.存储过程名称为foobar.它不需要参数,应该返回"你好".

5.看看它是否在那里,记得放回你的分隔符!:

 mysql> show procedure status;
 -> 
 -> 

疑难杂症!为什么这不起作用？你设置分隔符要//记住吗？把它重新设置为;

6.设置分隔符并查看过程:

mysql> delimiter ;
mysql> show procedure status;
+-----------+--------+-----------+----------------+---------------------+---------------------+---------------+---------+----------------------+----------------------+--------------------+
| Db        | Name   | Type      | Definer        | Modified            | Created             | Security_type | Comment | character_set_client | collation_connection | Database Collation |
+-----------+--------+-----------+----------------+---------------------+---------------------+---------------+---------+----------------------+----------------------+--------------------+
| yourdb    | foobar | PROCEDURE | root@localhost | 2013-12-06 14:27:23 | 2013-12-06 14:27:23 | DEFINER       |         | utf8                 | utf8_general_ci      | latin1_swedish_ci  |
+-----------+--------+-----------+----------------+---------------------+---------------------+---------------+---------+----------------------+----------------------+--------------------+
1 row in set (0.00 sec)

7.运行它:

mysql> call foobar();
+-------+
| hello |
+-------+
| hello |
+-------+
1 row in set (0.00 sec)
Query OK, 0 rows affected (0.00 sec)

你好世界完整,让我们用更好的东西覆盖它.

8.删除foobar,重新定义它以接受参数,然后重新运行它:

mysql> drop procedure foobar;
Query OK, 0 rows affected (0.00 sec)

mysql> show procedure status;
Empty set (0.00 sec)

mysql> delimiter //
mysql> create procedure foobar (in var1 int)
    -> begin select var1 + 2 as result;
    -> end//
Query OK, 0 rows affected (0.00 sec)

mysql> delimiter ;
mysql> call foobar(5);
+--------+
| result |
+--------+
|      7 |
+--------+
1 row in set (0.00 sec)
Query OK, 0 rows affected (0.00 sec)

太好了!我们制作了一个接受输入,修改它并输出的过程.现在让我们做一个变量.

9.删除foobar,创建一个变量,运行它:

mysql> delimiter ;
mysql> drop procedure foobar;
Query OK, 0 rows affected (0.00 sec)

mysql> delimiter //
mysql> create procedure foobar(out var1 varchar(100))
    -> begin set var1="kowalski, what's the status of the nuclear reactor?";
    -> end//
Query OK, 0 rows affected (0.00 sec)


mysql> delimiter ;
mysql> call foobar(@kowalski_status);
Query OK, 0 rows affected (0.00 sec)

mysql> select @kowalski_status;
+-----------------------------------------------------+
| @kowalski_status                                    |
+-----------------------------------------------------+
| kowalski, what's the status of the nuclear reactor? |
+-----------------------------------------------------+
1 row in set (0.00 sec)

10. MySQL中INOUT使用示例:

mysql> select 'ricksays' into @msg;
Query OK, 1 row affected (0.00 sec)


mysql> delimiter //
mysql> create procedure foobar (inout msg varchar(100))
-> begin
-> set msg = concat(@msg, " never gonna let you down");
-> end//


mysql> delimiter ;


mysql> call foobar(@msg);
Query OK, 0 rows affected (0.00 sec)


mysql> select @msg;
+-----------------------------------+
| @msg                              |
+-----------------------------------+
| ricksays never gonna let you down |
+-----------------------------------+
1 row in set (0.00 sec)

好吧它工作,它加入了一起.因此,您定义了一个变量msg,将该变量传递给名为foobar的存储过程,并且@msg由foobar写入.

现在您知道如何使用分隔符创建存储过程.继续本教程,从存储过程中的变量开始:http://net.tutsplus.com/tutorials/an-introduction-to-stored-procedures/

Answer 2

以下是带分隔符的示例MYSQL存储过程以及如何调用..

DELIMITER $$

DROP PROCEDURE IF EXISTS `sp_user_login` $$
CREATE DEFINER=`root`@`%` PROCEDURE `sp_user_login`(
  IN loc_username VARCHAR(255),
  IN loc_password VARCHAR(255)
)
BEGIN

  SELECT user_id,
         user_name,
         user_emailid,
         user_profileimage,
         last_update
    FROM tbl_user
   WHERE user_name = loc_username
     AND password = loc_password
     AND status = 1;

END $$

DELIMITER ;

并调用,mysql_connection规范和

$loginCheck="call sp_user_login('".$username."','".$password."');";

它将返回程序的结果.