Single line of text field validation in Sharepoint 2010 list

Question

I have single line of text field in a Sharepoint 2010 list. I need to validate the particular field. The user will enter the number by starting with I or F. How do I validate the field if the user does not enter the number starting with I or F?

For e.g., (the user will enter I1900 or F9999), but if the users enters without I or F(such as only number 9999) how do I validate this field?

Answer 1

When creating the column, expand the "Column Validation" section and you should see a text box where you can enter a formula.

To test if the first character of a column called "ToValidate" is I or F use:

=OR(LEFT(ToValidate,1)="I",LEFT(ToValidate,1)="F")

The syntax is basically Excel so you might want to test any other formulas in that first.

Answer 2

=OR(ISNUMBER(FIND("F";Title));ISNUMBER(FIND("I";Title))), Title - your field