Re: OK to delete records while finding them?
This WebDNA talk-list message is from 2000
It keeps the original formatting.
numero = 32479
interpreted = N
texte = >Is there some inherent danger in deleting a record from a db within >a [founditems] loop which is finding >records in that same db?Yes, this is bad. When you do a [SEARCH], webcat creates an internal list of record numbers. It then uses that list to call up the info from the correct lines. If you do a [DELETE], the internal list stays the same, but the info that's really in the database is wrong.For example, let's say your search returns the first, second, and third records in a database:Sku 1 2 3After the first [DELETE], your db might look like thisSKU 2 3So on the next iteration, webcat will look at the second line. Instead of finding the record with SKU=2, it will find the record with SKU=3. Since it doesn't know you don't want that, bad things happen.A simple solution is to replace a field with a unique phrase/word and then delete all those records after the [FOUNDITEMS] loop is complete (this will preserve the line numbering):[SEARCH db=some.db&neSKUdatarq=[SKU]] [FOUNDITEMS] [REPLACE db=some.db&eqSKUdatarq=[SKU]]SKU=DELETEME[/REpLACE] [/FOUNDITEMS] [/SEARCH] [DELETE db=some.dn&eqSKUdatarq=DELETEME]Michael------------------------------------------------------------- This message is sent to you because you are subscribed to the mailing list
. To unsubscribe, E-mail to: To switch to the DIGEST mode, E-mail to Web Archive of this list is at: http://search.smithmicro.com/
Associated Messages, from the most recent to the oldest:
>Is there some inherent danger in deleting a record from a db within >a [founditems] loop which is finding >records in that same db?Yes, this is bad. When you do a [search], webcat creates an internal list of record numbers. It then uses that list to call up the info from the correct lines. If you do a [delete], the internal list stays the same, but the info that's really in the database is wrong.For example, let's say your search returns the first, second, and third records in a database:Sku 1 2 3After the first [delete], your db might look like thisSKU 2 3So on the next iteration, webcat will look at the second line. Instead of finding the record with SKU=2, it will find the record with SKU=3. Since it doesn't know you don't want that, bad things happen.A simple solution is to replace a field with a unique phrase/word and then delete all those records after the [founditems] loop is complete (this will preserve the line numbering):[SEARCH db=some.db&neSKUdatarq=[SKU]] [founditems] [REPLACE db=some.db&eqSKUdatarq=[SKU]]SKU=DELETEME[/REpLACE] [/FOUNDITEMS] [/SEARCH] [DELETE db=some.dn&eqSKUdatarq=DELETEME]Michael------------------------------------------------------------- This message is sent to you because you are subscribed to the mailing list . To unsubscribe, E-mail to: To switch to the DIGEST mode, E-mail to Web Archive of this list is at: http://search.smithmicro.com/
Michael Winston
DOWNLOAD WEBDNA NOW!
Top Articles:
Talk List
The WebDNA community talk-list is the best place to get some help: several hundred extremely proficient programmers with an excellent knowledge of WebDNA and an excellent spirit will deliver all the tips and tricks you can imagine...
Related Readings:
Pithy questions on webcommerce & siteedit (1997)
Dates! (1998)
This is an odd error (2001)
Re:2nd WebCatalog2 Feature Request (1996)
Re:quit command on NT (1997)
Nested tags count question (1997)
Loops N Variables (1998)
Dealer locator (1998)
Webstar 1.3.1 PPC (1997)
Re:Emailer tracking (1997)
TCPConnect & Post (2002)
WCS Newbie question (1997)
OT: Unix Find Question (2004)
Robert Minor duplicate mail (1997)
Sort Order on a page search (1997)
[WebDNA] recommendations for installing on snow leopard (2010)
My slower response (1997)
[WebDNA] WebDNA glitch, no response required ... (2009)
PCS Frames (1997)
Unauthorized User trouble (1998)