[mysql] MySQL create stored procedure syntax with delimiter

I am trying to create a stored procedure in MySQL using a delimiter like this:

use am;

DELIMITER $$

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

END $$

DELIMITER ;

It gives me an error:

#1304 - PROCEDURE addfields already exists

What is the proper syntax for making a stored procedure with a delimiter and dropping it if it exists first?

I have created a simple MySQL procedure as given below:

DELIMITER //
CREATE PROCEDURE GetAllListings()
 BEGIN
 SELECT nid, type, title  FROM node where type = 'lms_listing' order by nid desc;
END //
DELIMITER;

Kindly follow this. After the procedure created, you can see the same and execute it.

MY SQL STORED PROCEDURE CREATION

DELIMiTER $$
create procedure GetUserRolesEnabled(in UserId int)
Begin

select * from users
where id=UserId ;
END $$
DELIMITER ;

Here is my code to create procedure in MySQL :

DELIMITER $$
CREATE DEFINER=`root`@`localhost` PROCEDURE `procedureName`(IN comId int)
BEGIN
select * from tableName 
         (add joins OR sub query as per your requirement)
         Where (where condition here)
END $$
DELIMITER ;

To call this procedure use this query :

call procedureName(); // without parameter
call procedureName(id,pid); // with parameter

Detail :

1) DEFINER : root is the user name and change it as per your username of mysql localhost is the host you can change it with ip address of the server if you are execute this query on hosting server.

Read here for more detail

Getting started with stored procedure syntax in MySQL (using the terminal):

1. Open a terminal and login to mysql like this:

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

2. Take a look to see if you have any procedures:

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)

I have one defined, you probably have none to start out.

3. Change to the database, delete it.

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)
    

4. Ok so now I have no stored procedures defined. Make the simplest one:

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

The // will communicate to the terminal when you are done entering commands for the stored procedure. the stored procedure name is foobar. it takes no parameters and should return "hello".

5. See if it's there, remember to set back your delimiter!:

 mysql> show procedure status;
 -> 
 -> 

Gotcha! Why didn't this work? You set the delimiter to // remember? Set it back to ;

6. Set the delimiter back and look at the procedure:

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. Run it:

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

Hello world complete, lets overwrite it with something better.

8. Drop foobar, redefine it to accept a parameter, and re run it:

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)

Nice! We made a procedure that takes input, modifies it, and does output. Now lets do an out variable.

9. Remove foobar, Make an out variable, run it:

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. Example of INOUT usage in MySQL:

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)

Ok it worked, it joined the strings together. So you defined a variable msg, passed in that variable into stored procedure called foobar, and @msg was written to by foobar.

Now you know how to make stored procedures with delimiters. Continue this tutorial here, start in on variables within stored procedures: http://net.tutsplus.com/tutorials/an-introduction-to-stored-procedures/