mySQL Create Procedure error + general mysql help - mysql

Question

Hi
I'm very very new at MySQL and was wondering if anyone could help me out.
I'm trying to build a procedure for my database and am using the following code.
CREATE PROCEDURE `createuser`(username VARCHAR(100), password VARCHAR(100), email VARCHAR(100)) BEGIN
DECLare returnValue int;
IF EXISTS(SELECT 'True' FROM User_Table WHERE(User_Username = username OR User_Email = email))
BEGIN
SET returnValue = 0;
END;
ELSE
BEGIN
SET returnValue = 1;
INSERT into User_Table(User_Username, User_Password,User_Email) VALUES(username, password,email)
END; END;
I'm getting a error on the BEGIN after the if statement. The error is "Bad syntax near "BEGIN SET returnvalue = 0; END ELSE;
Could you please tell me if im using the IF statement correctly in a mysql sence. It seems to work fine on a MSSql server but not on a Mysql.
Would it also be possible to point me in the direction of some good tutorials for this kinda stuff as the main MYSQL website isn't particularity user friendly.
Cheers

Answer 1

Instead of
IF statement
BEGIN
commands;
END
ELSE
BEGIN
commands;
END
use
IF statement THEN
commands;
ELSE
commands;
END IF;
Here is how I would write your procedure (changes may be a mixture of cosmetic changes and actual changes; suggest experimenting to find out which are which)
CREATE PROCEDURE `createuser` ( IN username VARCHAR(100),
IN password VARCHAR(100),
IN email VARCHAR(100)
)
BEGIN
DECLARE returnValue INT;
IF EXISTS (
SELECT 1
FROM User_Table
WHERE User_Username = username OR User_Email = email
) THEN
SET returnValue = 0;
ELSE
SET returnValue = 1;
INSERT INTO User_Table
(User_Username, User_Password, User_Email)
VALUES
(username, password, email);
END IF;
END;
You don't appear to be doing anything with the variable returnValue. You might need to declare this as OUT or INOUT, depending on what you want to do with it. I haven't got experience of using return values for stored procedures.