Re: Date or time comparisons have bugs ...
This WebDNA talk-list message is from 1998
It keeps the original formatting.
numero = 16983
interpreted = N
texte = Ken-The problem is not in your [Search] parameters, but in the fact that you are doing a [Delete] within a [FoundItems] loop.I'm sure that Grant can explain this better than I can, but when you do a search, WebCat creates its own internal list of matching items and remembers them by their positions in the database. [FoundItems] then loops through each of those records, first performing the desired operations on the first found record in the db, then on the second, etc. Having a [Delete] inside [FoundItems] messes this up, because it changes the position of records in your database.For example, say the [Search] finds records 1,2,and 6. On the first [FoundItems] loop, record 1 is deleted. With record 1 gone, the original record 2 becomes record 1, and every other record moves up a position (2->1, 3->2, 4->3, etc.). So when [FoundItems] comes through looking for record 2, it is really finding the original record 3, which may or may not have met the search criteria. The original record 2 gets skipped altogether.Of course, you can avoid all of this by building the search criteria into your [Delete]:[Delete db=this.db&ledeleteDatedatarq=[date]&ledeleteTimedatarq=[time]&deleteDatetype=da te]-Dave >Date: 9 Apr 1998 08:26:04 >From: Kenneth Grome
>Subject: Date or time comparisons have bugs ... > >I have three fields in this.db: cartID, deleteDate and deleteTime, >corresponding to the following data: > >296987757 02/10/1998 13:59:35 >296987758 02/10/1998 13:59:49 >296987760 02/10/1998 14:00:00 >297229722 03/10/1998 14:07:10 >297422049 04/01/1998 20:21:39 >297489625 04/09/1998 16:04:12 >297489636 04/09/1998 16:06:08 > > >My code, which is designed to delete records, looks like this: > >[search >db=this.db&ledeleteDatedatarq=[date]&ledeleteTimedatarq=[time]&deleteDatetype=d >ate] >[founditems] >[delete db=this.db&eqcartIDdatarq=[cartID]] >[/founditems] >[/search] > >So why doesn't it delete all but the last three records? > >Clearly it *should* delete the first 4 records because both the dates AND the >times are *less than* the current date and time, which is 04/08/1998 and >16:12:00 ... so, is there a bug in WebCatalog's code that's causing this >problem? > >Or is there a better way of coding this stuff so that it actually works? > >Sincerely, >Ken Grome >808-737-6499 >WebDNA Solutions >mailto:ken@webdna.net >http://www.webdna.net >o--------------- Dave MacLeay --+ o----------- Digital Frontier --+ o--- dave@digitalfrontier.com --+
Associated Messages, from the most recent to the oldest:
Ken-The problem is not in your [search] parameters, but in the fact that you are doing a [delete] within a [founditems] loop.I'm sure that Grant can explain this better than I can, but when you do a search, WebCat creates its own internal list of matching items and remembers them by their positions in the database. [founditems] then loops through each of those records, first performing the desired operations on the first found record in the db, then on the second, etc. Having a [delete] inside [founditems] messes this up, because it changes the position of records in your database.For example, say the [search] finds records 1,2,and 6. On the first [founditems] loop, record 1 is deleted. With record 1 gone, the original record 2 becomes record 1, and every other record moves up a position (2->1, 3->2, 4->3, etc.). So when [founditems] comes through looking for record 2, it is really finding the original record 3, which may or may not have met the search criteria. The original record 2 gets skipped altogether.Of course, you can avoid all of this by building the search criteria into your [delete]:[Delete db=this.db&ledeleteDatedatarq=[date]&ledeleteTimedatarq=[time]&deleteDatetype=da te]-Dave >Date: 9 Apr 1998 08:26:04 >From: Kenneth Grome >Subject: Date or time comparisons have bugs ... > >I have three fields in this.db: cartID, deleteDate and deleteTime, >corresponding to the following data: > >296987757 02/10/1998 13:59:35 >296987758 02/10/1998 13:59:49 >296987760 02/10/1998 14:00:00 >297229722 03/10/1998 14:07:10 >297422049 04/01/1998 20:21:39 >297489625 04/09/1998 16:04:12 >297489636 04/09/1998 16:06:08 > > >My code, which is designed to delete records, looks like this: > >[search >db=this.db&ledeleteDatedatarq=[date]&ledeleteTimedatarq=[time]&deleteDatetype=d >ate] >[founditems] >[delete db=this.db&eqcartIDdatarq=[cartID]] >[/founditems] >[/search] > >So why doesn't it delete all but the last three records? > >Clearly it *should* delete the first 4 records because both the dates AND the >times are *less than* the current date and time, which is 04/08/1998 and >16:12:00 ... so, is there a bug in WebCatalog's code that's causing this >problem? > >Or is there a better way of coding this stuff so that it actually works? > >Sincerely, >Ken Grome >808-737-6499 >WebDNA Solutions >mailto:ken@webdna.net >http://www.webdna.net >o--------------- Dave MacLeay --+ o----------- Digital Frontier --+ o--- dave@digitalfrontier.com --+
Dave MacLeay
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