Get the Average Value Across the Columns by Using the AVG() Function

CREATE TABLE tblSales (MonthNumber int,MonthName varchar(10) PRIMARY KEY,ProductA INT,ProductB INT,ProductC INT) INSERT INTO tblSales Select 1,'Jan',5800,5900,5400 union allSelect 2,'Feb',5750,5950,5500 union allSelect 3,'Mar',6200,5700,7100 union allSelect 4,'Apr',6300,5900,5400 union allSelect 5,'May',5350,5650,5500 SELECT A.*,X.AvgSales FROM tblSales A inner join(Select MonthName,Avg(Sales) AvgSales from(select MonthName,'A' Product,ProductA Sales FROM tblSalesunion allselect MonthName,'B' Product,ProductB Sales FROM tblSalesunion allselect MonthName,'C' Product,ProductC Sales FROM tblSales) A group by MonthName)Xon a.MonthName=x.MonthName  order by a.monthnumber