SQL Server - Invalid Use of a Side-Effecting Operator 'insert' within a Function

Here I will explain how to solve the problem of “invalid use of a side-effecting operator 'insert' within a function in SQL Server”.

Description: 

In previous posts I explained many articles relating to solve errors in asp.net, SQL Server, IIS, etc. Now I will explain how to solve the problem of “invalid use of a side-effecting operator 'insert' within a function in SQL Server”.

Generally this problem will occur whenever we try to write insert, update and delete queries inside of SQL Server functions like as shown below

CREATE FUNCTION [dbo].[testfunction] ( @LeadChannel VARCHAR(250), @UserId INT ) RETURNS INT AS BEGIN DECLARE @Channel INT Set @Channel  = 0 INSERT INTO PRESALE_LeadChannel(Source,Createdby) VALUES(@LeadChannel,@UserId) SELECT @Channel= @@IDENTITY RETURN @Channel END

In above function I written insert query because of that when we call this function we will get error like“invalid use of a side-effecting operator 'insert' within a function.”

To solve this problem we should not use insert, update and delete quries inside of functions.