[GRASS5] db.oodbfedit: a _very_ simplistic approach to dbf attribute editing

Daniel Calvelo Aros dcalvelo at minag.gob.pe
Fri Aug 5 20:20:35 EDT 2005


[me]
> > BTW, Moritz, have you tried the current CVS for extended SQL capabilities?
> > Please do so, and come up with wishes for extending it further. I've been
> > griping with NULL/NAN handling, but have come up with nothing concrete
> > yet.

[Moritz]
> Could you remind of what the new capabilities actually are, so that 
> I know what to test ?

See http://grass.itc.it/pipermail/grass5/2005-July/018981.html ; I patched CVS
last week.

> Last time I asked, this was the answer from Glynn
> (http://grass.itc.it/pipermail/grassuser/2005-June/029453.html):
> 
> ********
> > > Only a limited set of SQL functions and operators are currently supported.
> > >
> > > Addition is not among them.
> > >
> > > see the GRASS SQL help page:
> > >   http://grass.ibiblio.org/grass61/manuals/html61_user/sql.html
> >
> > Would the latest changes to the sql expression parser
> > (http://grass.itc.it/pipermail/grass5/2005-June/018588.html and
> > following) change this ?
> 
> No. Those changes just fix and extend the syntax of arithmetic
> expressions within WHERE clauses.
> **********
> 
> Is this still true ? One clear need was the possibility of including
> expressions in the update statement.

He, he. No, that's not true anymore. What you have now is (test please, test
please, test please):

update table foo set bar=baz/2+1/(-4*toto);

in addition to

select * from foo where 1-(-4)/bar=2+baz

Furthermore, in http://grass.itc.it/pipermail/grass5/2005-June/018589.html I
asked for testing an updated d.vect.thematic that handled (with the above
patches in the parser) thematic mapping from expressions.

Still TODO: after some more testing and certainly debugging, change the docs
to reflect current status.

Daniel.




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