"Duong Nguyen" <Duongnguyen@mail.ru> wrote in message
news:%23Nt9GqY4GHA.3964@TK2MSFTNGP04.phx.gbl...
> Hello,
> I have table with auto-id. Binding to a datagridview. One interesting
> moment:
> - the first time I run the application, I type some rows(in datagridview),
> and press onto Update (call method update of the tableAdapter). I got the
> error message: record with the Id = 1 already existed. I have tested with
> some other tables and every time I got the same error. But if I add only
> one row at the first time, then from the second time when I open this form
> to add many new rows and after that I press onto button Update it works ok
> (without any error message). Pls explain.

> thanks.
>
>
>
> --
> Contact:
> Bauman Moscow State Technical University
> Russia, Moscow 105005
> Tel: +7915-426-6272
> ICQ: 160-223-078
> YM: Chipheo2k
>

"Bart Mermuys" <b-m.NOSPAM@pandora.be> wrote in message
news:mhfSg.97774$mj5.1265761@phobos.telenet-ops.be...
> Hi,
>
> "Duong Nguyen" <Duongnguyen@mail.ru> wrote in message
> news:%23Nt9GqY4GHA.3964@TK2MSFTNGP04.phx.gbl...
>> Hello,
>> I have table with auto-id. Binding to a datagridview. One interesting
>> moment:
>> - the first time I run the application, I type some rows(in
>> datagridview), and press onto Update (call method update of the
>> tableAdapter). I got the error message: record with the Id = 1 already
>> existed. I have tested with some other tables and every time I got the
>> same error. But if I add only one row at the first time, then from the
>> second time when I open this form to add many new rows and after that I
>> press onto button Update it works ok (without any error message). Pls
>> explain.
>
> To support this auto-id in a batch mode, the DataColumn is set to
> AutoIncrement, then when the update is performed the DB generated keys are
> retrieved but *one* at a time.
>
> So, let's say you're adding three new records:
>
> id ...
> -- ---
> 0 ...
> 1 ...
> 2 ...
>
> The id's are generated by the DataColumn, now when you perform the update,
> the first row is inserted in the DB and it returns 1 as the key, but the
> second row currently also has 1 as the key, so it fails ...
>
> To avoid problems, set the DataColumn's AutoIncrementStep to -1, so the
> id's generated by the DataColumn are negative, while the ones generated by
> the DB are positive, this to avoid dupplicate keys *while* performing the
> update.
>
> To set the DataColumn's AutoIncrementStep, double click on your DataSet in
> solution explorer, select the id column inside the DataSet Schema Designer
> and then open properties window.
>
> HTH,
> Greetings
>
>
>> thanks.
>>
>>
>>
>> --
>> Contact:
>> Bauman Moscow State Technical University
>> Russia, Moscow 105005
>> Tel: +7915-426-6272
>> ICQ: 160-223-078
>> YM: Chipheo2k
>>
>
>