Re: [SQL] How to Convert Integer to Serial - Mailing list pgsql-general

On Fri, Oct 29, 2010 at 3:48 PM, venkat <ven.tammineni@gmail.com> wrote:

Dear All,

  I want to convert integer datatype to serial datatype.. is that possible.Please let me know.

I don't think ALTER TABLE will let you do that... so the best way to achieve the same is:

- Create a sequence for the column (set the start of sequence according to the values you got already in the column)

- Now set this sequence as the default value for that specific column which you need to ALTER like this:

ALTER TABLE tablename ALTER COLUMN columnname 
        SET DEFAULT nextval('newsequence'::regclass);

--
Shoaib Mir
http://shoaibmir.wordpress.com/