> Ivan Setya Darmawan wrote:
> > Hi,
> >
> > Assume I have 2 branch offices. One at Northpole and the other at
> > Southpole (brrbb). Each of them has a same customer table with fields
> > like this:
> >
> > customers
> > ----------------------
> > cust_id VARCHAR(20)(PK)
> > cust_name VARCHAR(80)
> >
> > And now has come consolidation day. I need to merge northpole customer
> > table and southpole customer table to a single customer table in
> > headquater database.
> >
> > I think, using autoincrement for cust_id is not a choice, coz it could
> > arise PK constraint error or cust_id replaced with new increment
> > value. So, I decide using before insert trigger for cust_id for each
> > table (including customers table at headquarter) like this:
> >
> > BEGIN
> > /* Trigger body */
> > IF (NEW.CUST_ID IS NULL) THEN
> > NEW.CUST_ID = RAND();
> > END
> >
> > and I hope merging those table become visible.
> >
> > Do I on right track here or anyone has many better ideas?
> >
> > TIA
> > #Ivan Darmawan
> >
>
> Hello,
>
> An usual solution to your problem might be that one table PK starts at 1
> and the other at 1.000.000.000 or whatever number is comfortable to you.
> Other solution is to have one PK as 'A'||<some_generator_value> and the
> other as 'B'||<some_generator_value>.
>
> HTH
> Radu

better still...
generators for PKs increment by 10 or 100 (being the number of server
stations you might one day have - maybe 10,000 stations! - so increment by
10000.
Your table in northpole has the generator set to 1 and your southpole DB has
gen set to 2.
northpoole records are 1, 11, 21, 31, 41, 51 etc
soutpole records are 2, 12, 22, 32, 42, 52, 62, 72 etc.
they never clash.
If you use bigint for PKs and have an expectation of 1000 server stations -
you do the math... there's still more records than humans on the earth times
humans on the earth for each and every station.

Alan