Hello Ken,
Unfortunately Pro does not have an Auto-ID feature like that found in
products like MS Access. However, you can assign a unique value to each
record in your table using a special field name "rowid". rowid is simply the
row number of the record and it's important to note that deleted rows do
have a rowid value. If you create a new field in your data ("ID" or
whatever), and use "Table > Update Column..." with rowid in the "Value" box,
you will assign your new field with the rowid.
This all looks simple enough but there is a point for concern. If your table
is being actively updated with records being added and deleted, you will
want to assign new IDs to the extra records. If however, you use the table
pack feature of Pro, all the deleted records will disappear and all the
rowid's will shuffle down. This means that a record that you assigned, say,
ID 123 to may not be rowid 123 any more. If you assigned rowid to ID for the
new records, there is a risk of assigning a value which is already used.
Have this in mind if maintenance of the unique value in a volatile table is
a requirement.
Regards,
Warren Vick
Europa Technologies Ltd.
http://www.europa-tech.com
-----Original Message-----
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED]]On Behalf Of Ken Hickey
Sent: Friday, March 01, 2002 11:11 PM
To: MapInfo-L
Subject: MI-L update column
G'day all
I have a relatively basic question I'd like to ask about updating a =
column in a MapInfo table. I have a map with a whole lot of regions on =
it. I now want to to label these with a unique ID number and the enter =
geological information about each one in a number of different fields. =
Is there a way for MapInfo to now automatically allocate a unique number =
in my ID field to each object in the table?
Thanks in advance
Chers
Ken Hickey
------------------------------------------------------------------
Dr Kenneth Hickey
Mineral Deposit Research Unit (MDRU)
Department of Earth and Ocean Sciences
University of British Columbia
6339 Stores Rd, Vancouver, BC V6T 1Z4, Canada
phone +1-604-822-3765; Fax +1-604-822-6088
email: [EMAIL PROTECTED]
=20
.
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