CREATE FUNCTION

Create a new Function

CREATE FUNCTION FirstWord (@input varchar(1000))
RETURNS varchar(1000)
AS
BEGIN
    DECLARE @output varchar(1000)
    SET @output = SUBSTRING(@input, 0, CASE CHARINDEX(' ', @input)
        WHEN 0 THEN LEN(@input) + 1
        ELSE CHARINDEX(' ', @input)
    END)

    RETURN @output
END

This example creates a function named FirstWord, that accepts a varchar parameter and returns another varchar value.

Syntax

CREATE FUNCTION function_name ( [list_of_paramenters] ) RETURNS return_data_type AS BEGIN function_body RETURN scalar_expression END

Parameters

|Argument|Description |---|---|---|--- |function_name|the name of function |list_of_paramenters|parameters that function accepts |return_data_type|type that function returs. Some SQL data type |function_body|the code of function |scalar_expression|scalar value returned by function

Remarks

CREATE FUNCTION creates a user-defined function that can be used when doing a SELECT, INSERT, UPDATE, or DELETE query. The functions can be created to return a single variable or a single table.