Обсуждение: alter varchar() column length?

Hello

CREATE TABLE foog(a varchar(10));
ALTER TABLE foog ALTER COLUMN a TYPE varchar(30);

postgres=# \d foog
            Table "public.foog"
 Column |         Type          | Modifiers
--------+-----------------------+-----------
 a      | character varying(30) |

regards
Pavel Stehule

On 11/01/2008, Gauthier, Dave <dave.gauthier@intel.com> wrote:
>
>
>
>
> Is there a way to alter a varchar column's length?  Maybe something like
> "alter table foo alter column xyz varchar(256)".
>
>
>
> My alternative seems very messy...
>
> -          alter table, add a new column with the desired varchar length.
> call it "temp"
>
> -          insert into "temp" the value of the old column.
>
> -          alter table, drop the old column (messing up all the indexes on
> that column in the process I suppose)
>
> -          alter table, add a new column with the same name as the one you
> just deleted, only with the desired length
>
> -          insert into that new column the value in "temp"
>
> -          alter table, drop "temp"
>
> -          recreate all the indexes
>
>
>
> Thanks
>
> -dave

Gauthier, Dave, 11.01.2008 15:55:
> Is there a way to alter a varchar column’s length?  Maybe something like
> “alter table foo alter column xyz varchar(256)”.

A quick look into the manual would have revealed the correct syntax:

http://www.postgresql.org/docs/8.2/static/sql-altertable.html