Generic Select Doesn't Work With Bit Type

based on this answer i tryed to create a Select for on of my table ALTER PROCEDURE _Einrichtung_Select -- Parameters with default values @EinrichtungId AS int

Solution 1:

It's because you can have null as values of your columns. And SQL have three-value logic, so checking null = null will return UNKNOWN instead of TRUE (as you may expect). I think this query will help you:

select *
frommyTablewhere
    (@EinrichtungId is null or EinrichtungId = @EinrichtungId) and
    (@EinrichtungName is null or EinrichtungName = @EinrichtungName) and
    (@IsKueche is null or IsKueche = @IsKueche) and
    (@RefEinrichtungId is null or RefEinrichtungId = @RefEinrichtungId) and
    (@RefSpeiseplantypId is null or RefSpeiseplantypId = @RefSpeiseplantypId)

sql fiddle demo