[V4RB] DELETE and Index Corruption

[Dave Addey]

Hi Gunnar,

No, each delete is with a separate cursor, which is a local cursor to a
delete function I created on a subclass of Vdatabase.  I call the delete
method separately for each row of the listbox that I want to delete.


Likewise with the SQLExecute approach, I have a method as part of the
Vdatabase subclass:

Sub RemoveSong(UniqueID as integer)
  
  Dim err as integer
  
  err = LibraryDB.SQLExecute("delete from ImportedSongs where UniqueID =
"+Str(UniqueID))

end Sub 


Is this bad practice, to add methods to a subclass of Vdatabase?  LibraryDB
is the name of my instance of the subclass.  Now I look at it, it should
probably be me.SQLexecute rather than LibraryDB.SQLExecute, but strictly
speaking it should still work as above.

Dave.

On 19/5/03 11:13 pm, "Gunnar Swan" <GunnarSwan at practicetopass.com> wrote:

> 
> Are you doing all deletes with the same cursor.
> Maybe create a new cursor or each record, delete the record, kill the cursor.
> Start with next record to delete.
> 
> 
> 5/19/03 3:13:09 PM, Dave Addey <support at dj1800.com> wrote:
> 
>> I have a vaguely similar problem, and it's driving me mad!
>> 
>> I have a database with 3,000 or so records.  One column is a Long field
>> called UniqueID, which is indexed and unique.
>> 
>> I load the contents of the database into a listbox.  The user can then
>> select multiple rows of the listbox.  When they press delete, I attempt to
>> delete all selected records by getting the UniqueID from a hidden column for
>> each row, one by one, and deleting the record with that UniqueID.
>> 
>> I have tried doing this multiple delete using an SQL statement, and also
>> using a VCursor.  I get the same problem in both cases.  When doing multiple
>> deletes one after another (as separate SQL statements), after a while some
>> deletes fail, even though they claim to work successfully (returning no
>> error).  Subsequently, my database can't find these entries with a "Select *
>> from [tablename] where UniqueID [a valid value]".
>> 
>> Interestingly, in this situation both my application and ViSQL can see these
>> records, but neither can delete them.  However, Valentina App can delete
>> these records.
>> 
>> This would imply that the index has got corrupted. Certainly, rebuilding the
>> index seems to help matters, but the next multiple delete fails in the same
>> way.
>> 
>> I have run a Diagnose on the database, and it comes up all okay.
>> 
>> Believe me, I have checked my code very thoroughly.  Flushing the database
>> makes no difference.  I have tried every possible way to avoid this, but to
>> no avail.
>> 
>> It's very annoying, as I can't think of a way round this!
>> 
>> For the record, I am using 10.2.5, Valentina 4 RB 1.9.7, REALbasic 4.5.2.
>> 
>> Please help!
>> 
>> Thanks in advance,
>> 
>> Dave. 
>> 
>> ------------------------------------
>> Dave Addey
>> dave at dj1800.com
>> 
>> DJ-1800
>> Complete MP3 DJ solution for the Mac
>> http://www.dj1800.com/
>> 
>> Support and pre-release forums:
>> http://dj1800.myforums.net/
>> 
>> _______________________________________________
>> Valentina mailing list
>> Valentina at lists.macserve.net
>> http://lists.macserve.net/mailman/listinfo/valentina
>> 
> 
> 
> Best Regards,
> Gunnar Swan
> http://www.PracticeToPass.Com
> 
> 
> 
> _______________________________________________
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> Valentina at lists.macserve.net
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> 

------------------------------------
Dave Addey
dave at dj1800.com

DJ-1800
Complete MP3 DJ solution for the Mac
http://www.dj1800.com/

Support and pre-release forums:
http://dj1800.myforums.net/