Re: Adding identity column to a non-empty table

Hi all,

I'd like to resurrect this thread, as it seems that there was no definitive
answer:
https://www.postgresql.org/message-id/959f28ef-4245-8349-eff9-0ff5f666df03%40lucee.org

Does anyone know how to add an IDENTITY column to an existing non-empty
table? Like Igal, I get the error message "column "id" contains null
values" when I try to do this:

ALTER TABLE test_table
ADD COLUMN id integer GENERATED ALWAYS AS IDENTITY;

And likewise with GENERATED BY DEFAULT. It seems strange that the column
does not populate itself when set to GENERATED ALWAYS.

From the test cases in src/test/regress/sql/identity.sql
<https://git.postgresql.org/gitweb/?p=postgresql.git;a=blob;f=src/test/regress/sql/identity.sql;h=e1b5a074c96102f3e1288325ae9a14c3acc90e50;hb=refs/heads/REL_10_STABLE#l19>,
it seems that this is by design, but it seems an unusual design choice to
force the user to jump through hoops to add an IDENTITY column.

Thanks, Chris.