On Thu, Nov 15, 2007 at 07:46:46PM +0530, ??????????????????????????? ?????? wrote: > On Nov 15, 2007 5:52 PM, Sam Mason <sam@xxxxxxxxxxxxx> wrote: > > What I tend to do here, is something like: > > > > CREATE TABLE test ( > > type INTEGER, > > ref1 INTEGER REFERENCES table1 CHECK ((type = 1) = (ref1 IS NOT NULL)), > > ref2 INTEGER REFERENCES table2 CHECK ((type = 2) = (ref2 IS NOT NULL)), > > ref3 INTEGER REFERENCES table3 CHECK ((type = 3) = (ref3 IS NOT NULL)) > > ); > > Thanks for sharing. Will try it. But, we have more than 10 types in > one table. Will be tough to handle. As Albe suggested, a view is about all that's going to help the poor people who work with this. When I do this sort of thing, I tend to find that there are very few queries that actually need everything all together in one place. It's generally that (using the naming above) that you'd do a query on "table1", "test" and something that references "test". Queries that reference "test", "table1" and "table2" are reasonably rare. Of course, it could be that I was just lucky here. Sam ---------------------------(end of broadcast)--------------------------- TIP 3: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faq