Re: List table with same column name

On Thu, 23 Oct 2003, Peter Childs wrote:

>
>
> On Thu, 23 Oct 2003 achill(at)matrix(dot)gatewaynet(dot)com wrote:
>
> > On Thu, 23 Oct 2003, Peter Childs wrote:
> >
> > >
> > >
> > > On Thu, 23 Oct 2003 achill(at)matrix(dot)gatewaynet(dot)com wrote:
> > >
> > > > On Thu, 23 Oct 2003, Abdul Wahab Dahalan wrote:
> > > >
> > > > > Hi!
> > > > > How do I list all the tables in the database which has a same column name?.
> > > >
> > > > SELECT t1.relname,a1.attname,t2.relname from pg_class t1,pg_attribute
> > > > a1,pg_class t2,pg_attribute a2 where a1.attrelid=t1.oid and t1.relkind='r'
> > > > and a1.attnum>0 and a2.attrelid=t2.oid and t2.relkind='r' and a2.attnum>0
> > > > and t1.relname<t2.relname and a1.attname = a2.attname;
> > >
> > > That will not work.
> > >
> > > SELECT t1.relname,a1.attname,t2.relname from pg_class t1,pg_attribute
> > > a1,pg_class t2,pg_attribute a2 where a1.attrelid=t1.oid and
> > > t1.relkind='r'and a1.attnum>0 and a2.attrelid=t2.oid and t2.relkind='r'
> > > and a2.attnum>0 and t1.relname<t2.relname and a1.attname = a2.attname and
> > > a1.attisdropped=false and a2.attisdropped=false and t1.relname !=
> > > t2.relname;
> > >
> > > Why?
> > >
> > > Well two bugs.
> > > 1> Dropped Columns needed for 7.3.
> > > 2> Do you really need to know that column a in table 1 also appears in
> > > table 1?
> >
> > Have you ever thought that x<y implies x!=y ?
>
> Yes but when I tested it due to pure intrest to told me that
> column a in table 1 also appeared in table 1. Most strange.

By adding x!= you probably influenced the ordering of the rows,
which gave you the impression of "solving" the "bug",
while actually the "bug" in the first place,
was an effect of a too large xterm that gives the illusion
of a left item to be the same as the right item of a
adjacent line.

Now seriously, if the meaning of x<y was not actually x<y for postgresql,
that would mean a general alarm, heads up, or whatever else we might
call it!

>
> Peter Childs
>
> >
> > >
> > > Peter Childs
> > >
> > > >
> > > > >
> > > > > Thanks
> > > > >
> > > > >
> > > > > ---------------------------(end of broadcast)---------------------------
> > > > > TIP 4: Don't 'kill -9' the postmaster
> > > > >
> > > >
> > > > --
> > > > -Achilleus
> > > >
> > > >
> > > > ---------------------------(end of broadcast)---------------------------
> > > > TIP 5: Have you checked our extensive FAQ?
> > > >
> > > > http://www.postgresql.org/docs/faqs/FAQ.html
> > > >
> > >
> >
> > --
> > -Achilleus
> >
> >
>
> ---------------------------(end of broadcast)---------------------------
> TIP 3: if posting/reading through Usenet, please send an appropriate
> subscribe-nomail command to majordomo(at)postgresql(dot)org so that your
> message can get through to the mailing list cleanly
>

--
-Achilleus