Home/ Questions/Q 5968955
In Process

The Archive Base Latest Questions

Editorial Team
  • 0
Asked: 2026-05-22T20:09:44+00:00

In our DB (on SQL Server 2005) we have a Customers table, whose primary

  • 0

In our DB (on SQL Server 2005) we have a “Customers” table, whose primary key is Client Code, a surrogate, bigint IDENTITY(1,1) key; the table is referenced by a number of other tables in our DB thru a foreign key.

A new CR implementation we are estimating would require us to change ID column type to varchar, Client Code generation algorithm being shifted from a simple numeric progression to a strict 2-char representation, with codes ranging from 01 to 99, then progressing like this:

1A -> 2A -> ... -> 9A -> 1B -> ... 9Z

I’m fairly new to database design, but I smell some serious problems here. First of all, what about this client code generation algorithm? What if I need a Client Code to go beyond 9Z code limit?

The I have some question: would this change be feasible, the table being already filled with a fair amount of data, and referenced by multiple entities? If so, how would you approach this problem, and how would you implement Client Code generation?

Share

Leave an answer

You must login to add an answer.

Need An Account,

1 Answer

  1. Editorial Team

    I would leave the primary key as it is and would create another key (unique) on the client code generated.
    I would do that anyway. It’s always better to have a short number primary key instead of long char keys.
    In some situation you might prefer a GUID (for replication purposes) but a number int/bigint is alway preferable.
    You can read more here and here.

    • 0