MYSQL - Using simple inventory number convention as Primary Key I have an inventory with three numbered groups like so:

Group 1: 0-999
Group 2: e0-e999
Group 3: v0-v999

Can I simply make a one-column table to store this information and make that column the primary index (needed?), or should I make it two columns.

example:

code (primary)
000
016
760
433
e221
e011
v999
v003


vs.

(primary)
 code_id    code
    1        000
    2        016
    3        760
    4        433
    5        e221
    6        e011
    7        v999
    8        v003
You can use the one-column approach for simplicity.  However, what happens when a code is changed?  Will you have to update all related tables to have the new code?

Using an integer ID is the best choice for a primary key because it's small and efficient (strings have to be reduced/hashed to an integer before they are used as an index).  Also, updating a code will happen in only one place and be reflected in all related tables automatically.

So I would recommend your second option for the sake of speed and to avoid a cascading update.