PostgreSQL: default_sequence_name falls back to 'id' pk if both the given pk and discovered pk are nil.
 r4336@asus:  jeremy | 2005-11-12 22:31:39 -0800
 PostgreSQL: correct the sequence discovery fallback query.  References #2594.


git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@2994 5ecf4fe2-1ee6-0310-87b1-e25e094e27de