Modify Column

On Friday 01 December 2000 10:23, joe@jwebmedia.com wrote:

This seems like a simple enough thing, and I'm sure it's been answered,
but I couldn't find anything that helped in the archives. Basically, I
have a column in my table that was, once upon a time, large enough, but
now, I need to increase the site of the column. How can I do that?
Thanks,

Joe

You can dump the database to file.sql, edit file.sql and change the size of
the column, save it, drop the database, and reload it from file.sql.

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I don't know if you can use ALTER TABLE to do this
but you could rename the old column, add a new column with
the right name and size and use an UPDATE statement to
copy the data in.

Unfortunately I had problems dropping the old column since
ALTER TABLE xxx DROP COLUMN zzzz is not implemented in
the version on p-sql I'm using - I wonder if its in a later release???
If not you might have to create a whole new table and copy the data
in with a INSERT INTO xxx SELECT * from zzz;

Hope this helps, maybe someone else knows the ultimate way of doing this :)

MC

joe@jwebmedia.com on 01/12/2000 15:23:03

Please respond to joe@jwebmedia.com

To: PostgreSQL General <pgsql-general@postgresql.org>
cc: (bcc: Martin Chantler/CIMG/CVG)
Subject: [GENERAL] Modify Column

This seems like a simple enough thing, and I'm sure it's been answered,
but I couldn't find anything that helped in the archives. Basically, I
have a column in my table that was, once upon a time, large enough, but
now, I need to increase the site of the column. How can I do that?
Thanks,

Joe

Thanks - It's a fairly small table so I decided to create a new field and
update the table. My syntax was
UPDATE tablename SET new_column = old_column WHERE uid = uid;
However it says: Relation 'tablename' does not have attribute 'new_column'

If i do \d tablename, it shows the new column. Did I miss a step? Thanks,

Joe

Len Morgan wrote:

This worked for me:

update pg_attribute set atttypmod = 104 where attname = 'column_name' and
attrelid = (select oid from pg_class where relname = 'tablename');

to set a varchar column 'columnname' in 'tablename' to a size of 100.

Tamsin