Re: List table with same column name - Mailing list pgsql-sql

On Thu, 23 Oct 2003, Peter Childs wrote:

> 
> 
> On Thu, 23 Oct 2003 achill@matrix.gatewaynet.com wrote:
> 
> > On Thu, 23 Oct 2003, Peter Childs wrote:
> >
> > >
> > >
> > > On Thu, 23 Oct 2003 achill@matrix.gatewaynet.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
> > > > >
> > > > >
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> > > > --
> > > > -Achilleus
> > > >
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> > --
> > -Achilleus
> >
> >
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-- 
-Achilleus