I have textbox1 and textbox2 and textbox3. I have a GridView using a SqlDataSource with the following SQL statement:
SELECT * FROM TABLE
WHERE column1 = @textbox1
OR column2 = @textbox2
OR column3 = @textbox3

Putting values into all three textboxes returns the results as expected. If I leave any of the text boxes blank, the gridview shows no results...

How can I show results without requiring values in all textboxes? (When I do a Test Query in VisualStudio it returns values without requiring values for all fields)