Thanks to all people who replied. Sorting the VTab doesn't seem to
be a big problem. Many solutions, tried a few, all of them worked.
However, none is suitable for my specific problem (unioning islands
with surronding polygons) since I have a theme with 25.000 shapes.
Sorting the Vtab everytime after unioning two polygons is not
practicable. (Note: dissolve does not work at all because of the
characteristics of the shapefile)
Finally I wrote a script that does the job: The attributes of the "big"
polygon that I want to retain are copied into a "dummyrecord" at the
end of the Vtab, any polygon resulting von unioning an island with
the surronding one will get its attributes from the dummy, the
dummy then will be deleted.
Roland

******************

Original question:

Hi,
how can I (preferably using an existing script or extension)
permanently change the order of records in a Vtab?
Attention: I don't want to simply "sort" a table. I really want to change
the order of records in the internal VTab. That means, for example
that a
polygon  that was created first gets in the last position of the Vtab so
that a loop like : "for each rec in myVTab" would address it last.

The reason why I want to achieve this is the following:
In a polygon theme I want to union small island polygons with
surronding bigger ones. There is no common pattern in that theme
which attributes the big ones and the islands have, therefor
"dissolve features" does not work in this case (Otherwise I could
create a "dissolve by" field in the table and so on. The "Union
command" however would do the job if not the ArcView rule for
assigning attributs to the resulting polygon would be as follows
(from the ArcView help):

" value in whichever record is FIRST in the table will be assigned "

So if I could rearrage the values in the VTab by sorting them using
the area of the polygons, I could use the union command and my
new polygons would  always get the attributes of the bigger one,
which is what I want. Remember: Just sorting the table does not do
the job!

I'm using 3.1

Thanks for replies

Roland



*******************
Answers
********************

Hi Roland,

Just wondered if you had tried editing the dbf files in Excel. You can
sort, add fields etc as you wish. Once finished you must use the
"Insert "
"Name" and "define" buttons in excel to redefine database range (if
you
have added new fields that is). Save the dbf file and then put it back
into Arcview. Hope this may help Ben

*************************

An easy way is to use the "Sort and Promote" script available at
http://www.quantdec.com/arcview1.htm .

--Bill Huber
Quantitative Decisions

*********************

You may try the Compiled table tools extension, it will save any sort
permanently

good luck...

Alberto Barud
GIS Coordinator
Center for Environmental Resource Management
The University of Texas at El Paso
(915) 747-7632


*************************
I am sure you will get lots of input on this issue, but unless you are
willing to write ( or find) code to read the shape file and create a
new
shape file ordered the way you desire, any sorting of the VTAB (.dbf
table) without modifying the index numbers stored in the shape
column to
keep them in correspondence with the coordinate strings in the
shape file
(.shp binary file) will corrupt the shape file format. ArcView expects
to
search the VTAB using direct reads of records based on their row
index
stored in the shape column and assumes that the file is sorted on
the
shape column index values. Take a look at a VTAB in Access and
you will
see the shape column contains index values linking the records to
their
corresponding coordinates in the .shp file.

Walt
*******************************

Hello Roland,
You might try the attached script which I grabbed off the ESRI
ArcScripts
page (keyword table).  You might also find other options from
ArcScripts
if you poke around some ("records", "sort"?).  Hope this helps.
Good
luck. Kathi Hannaford, Union Co. GIS khannaford@unionco.org


++++++++++++++++++++++++++++++
Dipl.-Geol. Dr. Roland Barthel
Universitaet Stuttgart
Inst. fuer Wasserbau
WAREM
Pfaffenwaldring 7a
70569 Stuttgart
Tel. 0711/685-6601
Fax. ++49-711-685-6600/-7020
email: roland.barthel@iws.uni-stuttgart.de