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16/11/2006 00:21:13
Dragan Nedeljkovich (En ligne)
Now officially retired
Zrenjanin, Serbia
 
 
Information générale
Forum:
Visual FoxPro
Catégorie:
Codage, syntaxe et commandes
Titre:
Versions des environnements
Visual FoxPro:
VFP 8 SP1
OS:
Windows XP
Database:
Visual FoxPro
Divers
Thread ID:
01170010
Message ID:
01170157
Vues:
14
>Vladimir,
>
>Thanks for your response, but I was not talking about SQL Server. I was talking about VFP native tables (not even part of database -free tables) and the ability to autoincrement field without using autoinc field added in VFP8. As far as I know the only other reliable method is to use a separate table to hold the latest ID (one record per table with ID). The approach is described in Craig Bernston's website and I used it myself successfully.
>
>Now I'm facing a situation when we're not using external table for IDs, but just taking the last ID from the table itself. I'm afraid there is no way to avoid possible duplicates, though with an immediate check we can minimize the risk. I don't know what to tell. That we should re-design the current approach?

Why not have a fake record with a key value of -1 (or some other preset value) and some other field which would hold the last key used? Then you'd have to lock that record, increment the value, read the value into a variable, unlock the record, add a new record with that value as the key. This way you do have a separate location which holds the key counter, only it's in the same table. Downside: you need one numeric field which wouldn't be included in any totals anywhere, i.e. a strange record you always have to filter out.

back to same old

the first online autobiography, unfinished by design
What, me reckless? I'm full of recks!
Balkans, eh? Count them.
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