After getting data from database,Add another column in result data set which
will hold your operation result. before binding to grid ,process it as you want (ie. check particular column value match with text box text) & update result in newly added column. After finishing it bind it to grid.
Or
Use row data bound event of grid. Bind your data set as it is to grid.In row data bound event .Process each grid row for your check condition & update result column in Grid view.
For row databound , check this
link