Question : How to create simple FUNCTION SQL and DO FUNCTION CALL

MYSQL
Mind to show me some example on How to create simple FUNCTION SQL and DO FUNCTION CALL and show result if can

Also can you explain abit why we need to use FUNCTION SQL?

Answer : How to create simple FUNCTION SQL and DO FUNCTION CALL

The link that elimesika supplied is really very good... answers all your questions.

But it does not have to be code - it can be SQL code....

delimiter //
CREATE FUCNTION HelloWorld() RETURNS VARCHAR(20)
BEGIN
    RETURN Hello World;
END
//
select HelloWorld() //


or something more adventurous from on-line help... and the the person who submitted it was richardkmiller

CREATE FUNCTION domain_of_url (url TEXT) RETURNS varchar(255) RETURN SUBSTRING_INDEX(SUBSTRING_INDEX(SUBSTRING_INDEX(TRIM(LEADING "https://" FROM TRIM(LEADING "http://" FROM TRIM(url))), "/", 1), ":", 1), ".", if(url LIKE "%.org.__%" OR url LIKE "%.net.__%" OR url LIKE "%.com.__%" OR url LIKE "%.__.us%" OR url LIKE "%.co.__%" OR url LIKE "%.__.uk%", -3, -2) );

SELECT domain_of_url(" http://www.richardkmiller.com:80/blog/ ") AS domain;




Have a look at : http://www.revealnet.com/newsletter-v6/0105_D.htm  
and part 2 on : http://www.quest-pipelines.com/newsletter-v6/0205_D.htm