Validation will limit the data to be entered in the selected row/column/cell. For example, in the student database, the maximum roll no is 50. Hence, if the user enters a roll no above 50, it should gives an error message.
Step 1: Enter Roll No in a cell A1 and select the entire column (column A)
Step 2: Go to Data → Validity, then a dialogue box will appear. In that, Go to Criteria Tab, Select whole numbers in the Allow field. It means only integer values are allowed. Fractional values are not allowed. In the Data Field, select less than and in the maximum field type 50. Refer Figure 11.16.
Then go to Error Alert Tab, in that select Show error message when invalid values are entered check box. Then select Warning in the Action checklist, Enter title of the error message (such as invalid) in the Title text box. Then Type the error message in the Error message multi line text box. Refer Figure 11.17.
Now, in the Roll No column, if the user types values above 50, the error message will appear as shown in Figure 11.18.