FUNCTIONS IN SUB PROGRAMS

Function can be used as a part of SQL expression i.e. we can use them with select/update/merge commands. One most important characteristic of a function is that, unlike procedures, it must return a value.
Syntax: Creating a function
CREATE [OR REPLACE] FUNCTION function_name
[(parameter_name type [, ...])]
// this statement is must for functions
RETURN return_datatype
{IS | AS}
BEGIN
// program code
[EXCEPTION
exception_section;
END [function_name];