A bit guess work, but I think the issue reported is as follows.  If you have a data grid and add a comparison search field that points to an integer field, it works as expected if you enter numeric values.  However, if you enter an alpha search term such as 'ab' instead of '10', you get no error, and the search does not happen - resulting in a list of all records.  The poster would expect no results to match the search term entered.

The short answer to the question is - don't do it.  But it would be nice if a warning was issued about inappropriate search term being ignored.