How can I add a column that doesn't allow nulls in a Postgresql database?

Question

I\'m adding a new, \"NOT NULL\" column to my Postgresql database using the following query (sanitized for the Internet):

ALTER TABLE mytable ADD COLUMN mycol         


        

Answer 1

You have to set a default value.

ALTER TABLE mytable ADD COLUMN mycolumn character varying(50) NOT NULL DEFAULT 'foo';

... some work (set real values as you want)...

ALTER TABLE mytable ALTER COLUMN mycolumn DROP DEFAULT;