MySQL CREATE FUNCTION Syntax

I am trying to create a function in MySQL:

Here is the SQL code:

CREATE FUNCTION F_Dist3D (x1 decimal, y1 decimal) 
RETURNS decimal
DETERMINISTIC
BEGIN 
 DECLARE dist decimal;
 SET dist = SQRT(x1 - y1);
 RETURN dist;
END;

I am getting the following error:

#1064 - You have an error in your SQL syntax; 
check the manual that corresponds to your MySQL 
server version for the right syntax to use near '' at line 10

I am running this create statement in phpMyAdmin. What is wrong with this function?

You have to override your ; delimiter with something like $$ to avoid this kind of error.

After your function definition, you can set the delimiter back to ;.

This should work:

DELIMITER $$
CREATE FUNCTION F_Dist3D (x1 decimal, y1 decimal) 
RETURNS decimal
DETERMINISTIC
BEGIN 
  DECLARE dist decimal;
  SET dist = SQRT(x1 - y1);
  RETURN dist;
END$$
DELIMITER ;

MySQL create function syntax:

DELIMITER //

CREATE FUNCTION GETFULLNAME(fname CHAR(250),lname CHAR(250))
	RETURNS CHAR(250)
	BEGIN
		DECLARE fullname CHAR(250);
		SET fullname=CONCAT(fname,' ',lname);
		RETURN fullname;
	END //
	
DELIMITER ;

Use This Function In Your Query

SELECT a.*,GETFULLNAME(a.fname,a.lname) FROM namedbtbl as a


SELECT GETFULLNAME("Biswarup","Adhikari") as myname;

Watch this Video how to create mysql function and how to use in your query

Create Mysql Function Video Tutorial