Learn SQL Database Programming

Syntax for functions

To create a function, you can use the following sample syntax:

DELIMITER $$ CREATE FUNCTION functionname( parameter1, parameter2,… ) RETURNS datatype [NOT] DETERMINISTIC BEGIN -- put sql statements here END $$ DELIMITER ;

To call the function in a SELECT query, you can use the following sample syntax:

SELECT col1, col2,        functionname(col3)FROM tablename; 

To alter the function, you need to delete it and recreate it with the following sample syntax:

DROP FUNCTION functionname;