I have a datagridview on a form with multiple columns. Three of the columns are expression columns. One column is subtracted from the second and the result is displayed in the third. Everything works great but when I hit the save button and save to the database, all the columns are saved to the database except the three columns used in the expression. They are NOT saved to the database. When I run the app in debug mode again the data in those 3 columns are gone. Is there something I am overlooking? How do you save expression data columns to the database?