Re: Filling Missing Primary Key Values

On Aug 11, 2011, at 12:34 PM, Rich Shepard wrote:

> On Thu, 11 Aug 2011, Chris Travers wrote:
>
>> The simplest seems to me to be a sequence and use nextval() to populate
>> the null values. The major advantage would be that the sequence could stay
>> around in case you need it again. So for example:
>>
>> create sequence my_varchar_values;
>
>> UPDATE my_table set my_varchar =
>> nextval('my_varchar_values')::varchar(12) where my_varchar IS NULL;
>
> Chris,
>
>  I was wondering if this was the best approach since I have new data to add
> to the table. Don't need a starting value, eh?

This will fail if any of the existing values are integers in the range that
you're inserting - and it may fail in the future, as you add new records
if they clash with existing entries.

It's still a good way to go, but might need some care or some tweaking -
adding a prefix, maybe.

Cheers,
  Steve