Question

Background Information

For some reason, while inserting a huge data into multiple tables from xml, my primary keys are shifted by an offset.. (Maybe because of multiple failed attempts :P)

I have two tables.. tableA and tableB. They are in one-to-may relationship.
tableA is the parent table and has the Primary key column …say DataIndex.

now DataIndex has come out like this..

685, 686, 687… and so on.

and corresponding values present in the child table i.e TableB are the same.

Problem

How do I shift the values up so that DataIndex start from 1, 2, 3..and so on; In both tables ?

Answer 1

I’m assuming that the primary key is actually an identity column that auto-increments itself upon insertion. What you will need to do is ‘reseed’ the identity column. You can do this by renaming the table, create a duplicate table with the original name, then inserting the data from the old table to the new one (the primary key field will be reset and will auto-increment from 1 again). When doing the insertion, make sure to include the old primary key value as an additional column for reference in the other tables.

To match up the related table, all you will need to do is do an UPDATE and join to your new table on the old primary key value:

UPDATE tableB SET
   PRIMARYKEYCOLUMN = tableA.PRIMARYKEYCOLUMN
FROM tableA
WHERE
   tableA.OLDPRIMARYKEYCOLUMN = tableB.PRIMARYKEYCOLUMN