add uuid primary key support

5 files changed, 30 insertions, 3 deletions

diff --git a/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb b/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb
index 3d0ddd3f5d..b358d84365 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb
@@ -64,8 +64,9 @@ module ActiveRecord
 
       # Appends a primary key definition to the table definition.
       # Can be called multiple times, but this is probably not a good idea.
-      def primary_key(name)
-        column(name, :primary_key, primary_key: true)
+      def primary_key(name, type = :primary_key, options = {})
+        options[:primary_key] = true
+        column(name, type, options)
       end
 
       # Returns a ColumnDefinition for the column with name +name+.
diff --git a/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb b/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb
index 6631a278ab..a26a0b54ea 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb
@@ -178,7 +178,7 @@ module ActiveRecord
             Base.get_primary_key table_name.to_s.singularize
           }
 
-          td.primary_key pk
+          td.primary_key pk, options.fetch(:id, :primary_key), options
         end
 
         yield td if block_given?
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb b/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb
index 923241b89f..0622d0a909 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb
@@ -10,6 +10,15 @@ module ActiveRecord
           add_column_options!(sql, column_options(o))
         end
 
+        def visit_ColumnDefinition(o)
+          sql = super
+          if o.primary_key? && o.type == :uuid
+            sql << " PRIMARY KEY "
+            add_column_options!(sql, column_options(o))
+          end
+          sql
+        end
+
         def add_column_options!(sql, options)
           if options[:array] || options[:column].try(:array)
             sql << '[]'
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
index 0a903d8aad..6f1eb25990 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
@@ -330,6 +330,13 @@ module ActiveRecord
       class TableDefinition < ActiveRecord::ConnectionAdapters::TableDefinition
         include ColumnMethods
 
+        def primary_key(name, type = :primary_key, options = {})
+          return super unless type == :uuid
+          options[:default] ||= 'uuid_generate_v4()'
+          options[:primary_key] = true
+          column name, type, options
+        end
+
         def column(name, type = nil, options = {})
           super
           column = self[name]
diff --git a/activerecord/test/cases/adapters/postgresql/uuid_test.rb b/activerecord/test/cases/adapters/postgresql/uuid_test.rb
index 53002c5265..c0c0e8898c 100644
--- a/activerecord/test/cases/adapters/postgresql/uuid_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/uuid_test.rb
@@ -35,6 +35,16 @@ class PostgresqlUUIDTest < ActiveRecord::TestCase
     @connection.execute 'drop table if exists pg_uuids'
   end
 
+  def test_id_is_uuid
+    assert_equal :uuid, UUID.columns_hash['id'].type
+    assert UUID.primary_key
+  end
+
+  def test_id_has_a_default
+    u = UUID.create
+    assert_not_nil u.id
+  end
+
   def test_auto_create_uuid
     u = UUID.create
     u.reload