ALTER FUNCTION [dbo].[GENERATE_MEMBERSHIP_ID] ( @agentId INT ) RETURNS VARCHAR(20) BEGIN DECLARE @MEMBESHIP_ID VARCHAR(15) ,@RANDOM_NUMBER VARCHAR(12), @maxValue INT SELECT @maxValue = ISNULL(maxValue, 1) FROM agentMaster (NOLOCK) WHERE AGENTID = @AGENTID SELECT @RANDOM_NUMBER = RIGHT('0000000' + CAST(@maxValue AS VARCHAR), 6) SET @MEMBESHIP_ID = 'IME' + @RANDOM_NUMBER RETURN @MEMBESHIP_ID; END SELECT dbo.GENERATE_MEMBERSHIP_ID('394390') --select maxvalue, * FROM agentMaster where agentid='394390' UPDATE customerMaster set membershipid=dbo.GENERATE_MEMBERSHIP_ID('394390') WHERE membershipid IS NULL