From: Johnny Withers [mailto:johnny@stripped]
Sent: Monday, May 11, 2009 3:30 PM
To: MySQL General List
Subject: Merging Databases
I have a lot of databases that have the exact same tables and each table has
the exact same column structure. I'm looking at merging two of these
databases together into a single database (Company A bought Company B and
wants the data from A combined into B now).
I've been tossing around the idea of looking in database B at each table
that would need to be "merged" and simply adding the last ID number to every
ID number in database A's tables. For example, in table1 in B's data, the
last ID number is 2000, could we simply add 2000 to every ID number in
table1 in A's data? Could we then export (SELECT INTO OUTFILE) from A's data
and import (LOAD DATA) into B's data?
Has anyone done something like this before? Did you have problems?
Why not create a view and just concatenate on an identifier? This way the data can be kept
in the same forms.
Or, if you do want to have it as one table, you can use a select insert statement to move
from one to another. Build the select query first to get the data looking like you want
it, then convert it when you think you are ready.
Of course, backups are your friend in any case. :)
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