Re: not so sequential sequences

rhys.stewart@gmail.com ("Rhys Stewart") writes:
> Hi all, looking for a method to number a table sequentially, but the
> sequence only increments if the value in a certain column is
> different. as in
>
>
> seq    |   parish
> ------------------------
> 1      | Kingston
> 1      | Kingston
> 1      | Kingston
> 1      | Kingston
> 2      | Lucea
> 3      | Morant Bay
> 3      | Morant Bay
> 3      | Morant Bay
> 4      | Port Antonio
> 5      | Savannah-La-Mar
> 5      | Savannah-La-Mar
> 5      | Savannah-La-Mar
>
> so i guess i would order by a certain column and then the 'magic
> sequence' would be a column that only increments when the column
> changes.

The usual way to do this would be to separate out what clearly is a
dependant table; the seq and parish values could be associated with a
smaller table that increments any time you get a new parish.

The process of doing this sort of separation is called "normalization."
<http://en.wikipedia.org/wiki/Database_normalization>
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