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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:
01170810
Vues:
14
>>Hi everybody,
>>
>>AFAIK there is no way in multi-user environment to have ID field incremented correctly without using extra table to keep the last ID (if we're not using autoincrement field). Using go bottom, grab the last number and start from there doesn't prevent two users from taking the same ID. Even if we put a check right after for the existance of ID.
>>
>>What do you think? Given only one table and no auto-increment is it possible to correctly auto-increment in multi-user environment?
>>
>>Thanks.
>
>I have another idea.
>You always can create a new table when you start the application. Then you could use this table as key generator. That way first user started the application will create this table.
>
>lcTableName = path_to_data_folder+[MyKeyGenTable]
>IF EMPTY(SYS(2000),lcTableName+[.DBF])
>   CREATE TABLE (lcTableName) FREE (NewKey I)
>   SELECT MAX(Id)+1 FROM Invoice INTO ARRAY laInvKey
>   INSERT INTO (lcTableName) VALUES (laInvKey[1])
>   USE IN SELECT([MyKeyGenTable])
>   USE IN SELECT([Invoice])
>ENDIF
>
Thanks, this seems like a good idea. I also agree with Fabio and Peter, so either one of these ideas should work.
If it's not broken, fix it until it is.


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