Re: Alter definition of a column

I haven't used it this way, anyone else who did might be able to comment on
it. Why will you not like to use the ALTER table command? I think a text
should be use in case you don't know the limit for characters (much faster
too in that case I guess) in a column but if you know the limits then you
should be using varchar(n).

-----------------
Shoaib Mir
EnterpriseDB (www.enterprisedb.com)

On 1/20/07, Kelly Burkhart <kelly(dot)burkhart(at)gmail(dot)com> wrote:
>
> On 1/20/07, Shoaib Mir <shoaibmir(at)gmail(dot)com> wrote:
> > Should help --> ALTER TABLE tablename ALTER columname TYPE text;
>
> I was looking for a way to alter a column from varchar(n) to text
> without using the alter command and consequently touching every single
> row. Below is sql which seems to work, but is it advisable to do such
> shenanigans? (are varchar and text the same thing)?
>
> kelly=# create table foo( c1 varchar(4) not null, c2 text not null );
> CREATE TABLE
> kelly=#
> kelly=# update pg_attribute set atttypid=25, atttypmod=-1
> kelly-# where attname = 'c1' and attrelid =
> kelly-# (select oid from pg_class where relname = 'foo');
> UPDATE 1
> kelly=#
> kelly=# \d foo
> Table "public.foo"
> Column | Type | Modifiers
> --------+------+-----------
> c1 | text | not null
> c2 | text | not null
>