PostgreSQL: more robust sequence name discovery. References #3087.

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@3235 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

activerecord/CHANGELOG

@@ -1,5 +1,7 @@
 *SVN*
 
+* PostgreSQL: more robust sequence name discovery.  #3087 [Rick Olson]
+
 * Oracle: use syntax compatible with Oracle 8.  #3131 [Michael Schoen]
 
 * MySQL: work around ruby-mysql/mysql-ruby inconsistency with mysql.stat.  Eliminate usage of mysql.ping because it doesn't guarantee reconnect.  Explicitly close and reopen the connection instead.  [Jeremy Kemper]

activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb

@@ -251,7 +251,7 @@ def pk_and_sequence_for(table)
         # First try looking for a sequence with a dependency on the
         # given table's primary key.
         result = execute(<<-end_sql, 'PK and serial sequence')[0]
-          SELECT attr.attname, (name.nspname || '.' || seq.relname)
+          SELECT attr.attname, name.nspname, seq.relname
           FROM pg_class      seq,
                pg_attribute  attr,
                pg_depend     dep,
@@ -274,7 +274,7 @@ def pk_and_sequence_for(table)
           # the 8.1+ nextval('foo'::regclass).
           # TODO: assumes sequence is in same schema as table.
           result = execute(<<-end_sql, 'PK and custom sequence')[0]
-            SELECT attr.attname, (name.nspname || '.' || split_part(def.adsrc, '\\\'', 2))
+            SELECT attr.attname, name.nspname, split_part(def.adsrc, '\\\'', 2)
             FROM pg_class       t
             JOIN pg_namespace   name ON (t.relnamespace = name.oid)
             JOIN pg_attribute   attr ON (t.oid = attrelid)
@@ -285,7 +285,8 @@ def pk_and_sequence_for(table)
               AND def.adsrc ~* 'nextval'
           end_sql
         end
-        result
+        # check for existence of . in sequence name as in public.foo_sequence.  if it does not exist, join the current namespace
+        result.last['.'] ? [result.first, result.last] : [result.first, "#{result[1]}.#{result[2]}"]
       rescue
         nil
       end

activerecord/test/fixtures/db_definitions/postgresql.sql

@@ -1,10 +1,11 @@
+CREATE SEQUENCE public.accounts_id_seq START 100;
+
 CREATE TABLE accounts (
-    id serial,
+    id integer DEFAULT nextval('public.accounts_id_seq'),
     firm_id integer,
     credit_limit integer,
     PRIMARY KEY (id)
 );
-SELECT setval('accounts_id_seq', 100);
 
 CREATE SEQUENCE companies_nonstd_seq START 101;