Olaf,

Du sagst, I habe ein Form und ein SubForm !!!

May I ask you wich development enviroment are you using for the front-end 
application ? I see this kind of application building as having been built with 
MsAccess !!! Because I work with VB, C# and Delphi, and I found this only with 
the Office family !

If you have separated forms (sub forms included) for both - parent and child 
table -, I see that you probably don´t have a only one transaction for both sql 
commands.... do you use explicit transaction in your application ?....

After you comment so:
>>2. Have you the same transaction for master detail 
>Both tables are linked to the firebird database over the firebird odbc driver. 
>After I insert the master 
>record and klick into the detail-form, I get the generated Nr back from 
>firebird (before I insert a detail 
>data set). I’m sorry, I don’t know how the driver works in detail. 

... you don´t talk explicitly something about this. Making this sequence of 
operations doesn´t mean you have a common transaction. If you don´t explicitly 
start a transaction, you will not have a transaction for both commands.

Roberto Camargo,
aus Brasilien



On Friday, December 6, 2013 7:45 AM, checkmail <check_m...@satron.de> wrote:
 



Hello @ll,
 
Today,I still could notreproducetheerroragain. What I can say, that I’m the 
only one in my test environment who creates records and the error also occurred 
there.
 
I can try to create a generator instead of the max-statement and I will see.
 
Of course, severalpeople work at the same time (customer) in the database, but 
locally I’m the only one and the problem already exists. I don’t know what 
exactly the error provoked. Currently I have create 100 records and every 
works. I’m confused.
 
Thanks a lot.
 
Best regards
 
Olaf
 
Von:firebird-support@yahoogroups.com [mailto:firebird-support@yahoogroups.com] 
Im Auftrag von Svein Erling Tysvær
Gesendet:Donnerstag, 5. Dezember 2013 11:42
An: firebird-support@yahoogroups.com
Betreff: RE: [firebird-support] difficult question
 
  
>>>I have a table with orders and a second table with orderpositions. The 
>>>composite primary key from orders 
>>>consists of jahr and nr, the orderpositions references with a foreign key to 
>>>this table and its primary 
>>>key is a continual ID. 
> 
>>>In my Frontend there is a form with the orders and a sub-form with the 
>>>positions – the data-side of both 
>>>forms is connected over jahr and nr. Now I can create a order, in main-form 
>>>I select a supplier and 
>>>select some articles in my sub-form. Ideally – it works fine. But in some 
>>>case (notably if in the order 
>>>before it is the same supplier) I select one or more parts to order and If 
>>>the form will refresh, the 
>>>order-positions from the order before are in the actually order! If I close 
>>>the form and reopen it again, 
>>>the last orderpositions and in the order before there are the from the last 
>>>order. The same situation I 
>>>have with a different odbc-driver and some other versions of Access. I’m 
>>>confused and the problem exists 
>>>for some years! One from 50 orders goes wrong in this way, the same problem 
>>>exists in some other areas 
> 
>>1. How you generate pk keys 
>Master: In this case I generate it with select max(nr)+1 from xxx where 
>new.jahr… I know, not the best way. 
>Detail: NEW.ID = GEN_ID(TBESTPOS_ID_GEN, 1); (generator) 
> 
>>2. Have you the same transaction for master detail 
>Both tables are linked to the firebird database over the firebird odbc driver. 
>After I insert the master 
>record and klick into the detail-form, I get the generated Nr back from 
>firebird (before I insert a detail 
>data set). I’m sorry, I don’t know how the driver works in detail. 

Transactions are vital in Firebird, I don't use ODBC with Firebird and don't 
know how to control transactions in your environment. What I think can be a 
possible cause, is if the master and detail query are in separate transactions. 
Then I can imagine one user inserting a new master with, say, ID 51, and a few 
detail records (say ID 101, 102, 103). Then another user (before the 
transaction of the other master is committed) tries to insert another master, 
but since the other master isn't committed yet, this ID also is 51. This user 
also insert detail records (say ID 104, 105). Upon committing, the first user 
will succeed with his inserts, whereas the other user will get a lock conflict 
for the transaction for the master and succeed for the transaction with the 
detail records. Normally, this second user should get an error message, but it 
is of course possible to suppress that in your program. Hence you may end up 
with one master with ID 51 and detail 101,
 102, 103, 104 and 105, whereas the other master isn't inserted at all. 

If this is the reason, the simple way to fix things would be to start using one 
or more generators for the master (you may have a separate generator for each 
jahr, or reset the generator each jahr if jahr is always the current year). 

HTH, 
Set 

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