Re: Finding Max Value in a Row

On 05/11/2012 12:30 PM, Carlos Mennens wrote:
> Thanks for all the help thus far everyone! I sadly didn't
> create/design the table and would love to create a SEQUENCE on that
> particular field but not sure how unless I DROP the table and create
> from scratch.
>
> Currently the data TYPE on the primary key field (users_id) is CHAR
> and I have no idea why...it should be NUMERIC or SERIAL but it's not
> so my question is if I want to ALTER the column and create a sequence,
> would I simply do:
>
> ALTER TABLE users
> ALTER COLUMN users_id TYPE serial
> ;
>
> Obviously if any of the data stored in users_id is actual CHAR, I'm
> guessing the database would reject that request to change type as the
> existing data would match. However the data type is CHAR but the field
> values are all numeric from 1000000010 - 1000000301 so I'm hoping that
> would work for SERIAL which is just INTEGER, right?
>

Well the question to ask is if it is declared CHAR was that done for a
legitimate reason? One reason I can think of is to have leading 0s in a
'number'. Might want to double check that code downstream is not
depending on CHAR behavior.

--
Adrian Klaver
adrian(dot)klaver(at)gmail(dot)com