> if one of the fields (civ, name or forname) is null, identity is
> null... That doesn't seems right, since it means that 1+2+0 = 0 !!!!
The crux of the matter is that zero and null aren't the same thing. Null
means in essence "We don't know", so this equation is better writtin as:
1+2+"don't know" = "don't know"
> is there a
> way to work
> this around ?
It *is* often true that when concatenating strings, we want to tell SQL "if
this value is null, treat it like an empty string". This is how you would do
it:
coalesce( civ,'')||coalesce(name,'')||coalesce(forname,'')
Regards,
-Nick
