"Joshua D. Drake" <jd@xxxxxxxxxxxxxxxxx> writes: > On Wed, 2010-02-24 at 20:22 +0000, Richard Huxton wrote: >> ALTER TABLE t ALTER COLUMN c TYPE integer USING c::integer; > That won't work in this case. char() can't be cast to int/numeric. Not > only that it isn't possible to clean up the data in table because char > automatically pads. > postgres=# alter table foo alter column id type numeric; > ERROR: column "id" cannot be cast to type "pg_catalog.numeric" That just indicates that there isn't an *implicit* coercion from char to numeric. With a USING clause you can specify an arbitrary conversion. I agree with the recommendation to test it out before actually doing the table change though. Maybe look at the results of select id, id::numeric from your_table to see if it looks sane for all the different data formats in the column. regards, tom lane -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
