How to narrow SQL search with multiple criterias?

[Tiemo Hollmann TB]

Hello,

I have seen this feature before, but have no idea what approach is behind
the scenes since I am not that deep in SQL.

I have a SQL select with multiple search criterias. After selecting a
criteria, I get the resulting records and can go on narrowing my search with
selecting one or multiple other criterias. So far nothing special. What I am
interested in is, how do you show (and disable) one or multiple search
criterias, if they would be inaffective for further searches, because there
is no content left to narrow the search with this criteria.

 

I could think of looping through the result for each criteria after having
made one selection and if there is nothing left to search for then disable
the search criteria. But with multiple search criterias, each with multiple
options, I don't know if this would be "state of the art" to keep a good
performance, or if there are more sophisticated approaches to let the user
just make click-click-click narrowing his search with simultaneous showing,
what other selection makes sense and what not.

 

Hoping you understood what I mean J

Thanks for any idea

Tiemo