Subject RE: [IBO] GeneratorLinks in 5,000,000 words or less
Author Helen Borrie
At 04:11 PM 07-02-01 -0500, you wrote:
>Hello Paul
>GeneratorLinks is to allow IBO to go ahead and get the
>ID of the record before the actual insert. This allows
>it to pass it along to Detail tables that could be connected
>and other things. You don't have to use it for positioning,
>I think you are talking about keylinks.
>I use the following trigger on my tables:
> create trigger TRGBEFINS_Customer for Customer
> active before insert position 0
> as
> begin
> if ((new.Cus_ID is NULL) or (new.cus_ID = 0)) then
> begin
> new.Cus_ID = gen_id (Gen_Customer_ID, 1);


The following code is !!!! dangerous !!!!. Generators operate right
outside the transaction context. In a multi-user environment, you are
certain to get PK violations. Don't do it!!!

> end else begin
> Temp_ID = gen_id(Gen_Customer_ID,0);
> if (new.CUS_ID > Temp_ID) then
> begin
> Temp_ID = gen_id(Gen_Customer_ID, new.Cus_ID-Temp_ID);
> end
> end
> end
>It will update your generator if necessary and also, make
>sure that the generator doesn't get behind if you inserted
>records that had IDs not derived from the generator.

If you are using a generator to populate a primary key, you should NEVER
try to insert rows where the PK comes from another source that **that**

To add a further note on GeneratorLinks, you should always use it when
inserting into a bi-directional dataset, rather than waiting until after
the insert has committed, to ensure that the KeyLinks will work
properly. Reserve the use of the trigger for external clients or scripts.


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