Hi

nobody know why

INDEX ON DESCEND(campo) TO PIPPO

ok with NTX
not work with CDX

grazie
Luca

I think there is a issue with descend and CDX...

HTH,

Best regards,

Bruce

Luca wrote:
> Hi
> 
> nobody know why
> 
> INDEX ON DESCEND(campo) TO PIPPO
> 
> ok with NTX
> not work with CDX
> 
> grazie
> Luca
> 
>

Bruce Carroll wrote:

> I think there is a issue with descend and CDX...
> 
> HTH,

At least there is no open PDR for descend and CDX index files.

But if Luca could post more details, e.g. a small sample showing the
problem, we may be able to help here.

"not work with CDX" is not a very detailed problem description 

Thomas

Luca,

> nobody know why
> 
> INDEX ON DESCEND(campo) TO PIPPO
> 
> ok with NTX
> not work with CDX

Just for starters, CDX indexes are by default, case-insensitive, so these
keys:

Recno   Key
-----------
1       Alpha
2       Beta
3       alpha

...come out as:

ALPHA
ALPHA
BETA

Without examining the index key itself, there is no way to determine which
of the first two keys points to which record.  Putting descend on them will
only add more confusion.

Regards,

Phil Ide

---------------------
www.xbhcl.com
www.pbih.eu
www.idep.org.uk/xbase
---------------------
Rather than having only one secret escape pod, which the hero can easily
spot and follow, I'll simultaneously launch a few dozen decoys to throw him
off track.
          [Things I'd do as an Evil Overlord]

Thanks Phil

INDEX ON campo2 TAG "1" TO PIPPO DESCENDING
... work correctly

INDEX ON campo1+DESCEND(campo2) TAG "2"  TO PIPPO
.... problems .. (15years in clipper was correctly)

so I REINDEX cdx in clipper and than exe in xbase 1.9 works correctly and
seem update correctly...



"Phil Ide" <phil@idep.org.uk> ha scritto nel messaggio
news:1urutyz4apqib.19o4i77kpf35b$.dlg@40tude.net...
> Luca,
>
> > nobody know why
> >
> > INDEX ON DESCEND(campo) TO PIPPO
> >
> > ok with NTX
> > not work with CDX
>
> Just for starters, CDX indexes are by default, case-insensitive, so these
> keys:
>
> Recno   Key
> -----------
> 1       Alpha
> 2       Beta
> 3       alpha
>
> ...come out as:
>
> ALPHA
> ALPHA
> BETA
>
> Without examining the index key itself, there is no way to determine which
> of the first two keys points to which record.  Putting descend on them
will
> only add more confusion.
>
> Regards,
> -- 
> Phil Ide
>
> ---------------------
> www.xbhcl.com
> www.pbih.eu
> www.idep.org.uk/xbase
> ---------------------
> Rather than having only one secret escape pod, which the hero can easily
> spot and follow, I'll simultaneously launch a few dozen decoys to throw
him
> off track.
>           [Things I'd do as an Evil Overlord]

Luca,

If you use the Descend() function for character strings, it is (normally) 
affected by the Character Set (OEM or ANSI) and your Collation Table, which 
also makes it usually case-insensitive. The "DESCENDING" clause for the 
"INDEX ON" command on the other hand simply reverses the established Tag 
order! 

To get Clipper-compatible indexes, you could try with:

INDEX ON campo1 + Descend(campo2, .f.) TAG "2" TO PIPPO

If this doesn't work, you could create and use your own Collation Table, 
using the SetCollationTable() function.

-- Andreas

---                                                                      ---
  Andreas Gehrs-Pahl              E-Mail: GPahl@CharterMI.net
  415 Gute Street                     or: Andreas@DDPSoftware.com
  Owosso, MI 48867-4410               or: Andreas@Aerospace-History.net
  Tel: (989) 723-9927           Web Site: http://www.Aerospace-History.net
---                                                                      ---