Re: matrix transpose in SQL?

how much will you pay me to send you the solution in SQL ?

"Aakash Bordia" <a_bordia_at_hotmail.com> wrote in message news:9cpekc$flk$1_at_stlnews.stl.ibm.com...
> Agreed! But do you have any SQL solution to my root problem? If yes,
 please
> guide me!
> Thanks
> Aakash
> "Vadim Tropashko" <nospam_at_newsranger.com> wrote in message
> news:ulhG6.959$SZ5.77667_at_www.newsranger.com...
> > In article <u766fqu11o.fsf_at_sol6.ebi.ac.uk>, Philip Lijnzaad says...
> > >
> > >
> > >> Why are you insisting that matrix must be modeled in RDBMS that way?
 There
> > >> is a symmetry between rows and columns in matrix, and you loose it in
 your
> > >> representation.
> > >
> > >Yes, I agree: this table:
> > >
> > >> 1 2 3
> > >> 4 5 6
> > >> 7 8 9
> > >
> > >is _not_ a matrix. It is an _unordered_ set of rows of numbers. This:
> > >
> > >> 1 2 3
> > >> 7 8 9
> > >> 4 5 6
> > >
> > >is exactly the same table, and in fact the SQL standard does not
 guarantee
> > >that the order of rows you get from a query is always the same, not
 even
 when
> > >when no updates to the table happened (although in practice it usually
 does).
> > >
> > >The cleanest way to represent matrices is of course:
> > >
> > >I J VALUE
> > >1 1 1
> > >1 2 2
> > >1 3 3
> > >2 1 4
> > >2 2 5
> > >2 3 6
> > >3 1 7
> > >3 2 8
> > >3 3 9
> > >
> >
> > Aakash,
> >
> > If those ideas were not convincing enough, think of matrix as just a
 tensor of
> > the second rank. Would you ever represent a tensor of rank 3 like this
> >
> > dim | a11 | a12 | a21 | a22
> > ---------------------------
> > 1 | 111 | 112 | 121 | 122
> > 2 | 211 | 212 | 221 | 222
> >
> > ?
> >
> >

>
> Received on Thu May 03 2001 - 05:05:43 CEST