Andrew wrote: > > Jim C. Nasby wrote: > >Personally, I don't see why enum can't just be syntactic sugar on top of > >a side-table of values and a foreign key. And I guess a view to hide the > >internals from normal viewing. That would certainly allow the most > >flexibility, although it probably wouldn't perform as well as what you > >wrote. > The other issue is ease of use. > > We used lookup tables in bugzilla when it was converted to work with > Postgres. But many users will find having to do that annoying, to say > the least. I think there's a very good case for providing true enums. > There is a technical part of the puzzle I can't quite see yet, though :-)
Hm, I agree with Jim here. IMO, enum=FK syntax sugar...enum should be a lookup table with two fields, one being enum value which is the PK, and two being the sequencing value. I think many people are opposed to this approach because they assume this relationship is via ID-ID link (IIRC this is what mysql does under the hood). In fact, the enum table's only purpose is for constraint checking, not to lookup the value (there is no 'id'). I like the way sequences work. They are first class SQL objects although they are normally accessed via helper functions. Enums could be the same. Dependancy could be preserved to the creating table or not (I prefer not). Merlin ---------------------------(end of broadcast)--------------------------- TIP 5: don't forget to increase your free space map settings
