Functions

Functions are same to an operator. The function is manipulating data items and returns a result. It  differ  from  operators  in  the  format  in  that  they  appear  with  arguments. Functions can be widely categorized into two types they are as follows.

•Built-In Functions

•User-Defined Functions Built-in functions are predefined functions which perform a specific task. Built-in functions based on the values in which they take to perform a task, can be classified into two types which are.

•Scalar or Single-Row Functions

•Aggregate or Group Functions

A single row function returns a single result row for each row of a queried table or view, whereas a group or aggregate function works on a group of rows. This section deals shortly with the several kinds of Single-Row functions.