1 files changed, 15 insertions, 5 deletions
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 c09e7a55e0..ec4d2de07e 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb
@@ -93,6 +93,12 @@ module ActiveRecord
                                       (!options.key?(:null)      || c.null == options[:null]) }
       end
 
+      # Returns just a table's primary key
+      def primary_key(table_name)
+        pks = primary_keys(table_name)
+        pks.first if pks.one?
+      end
+
       # Creates a new table with the name +table_name+. +table_name+ may either
       # be a String or a Symbol.
       #
@@ -220,7 +226,11 @@ module ActiveRecord
             Base.get_primary_key table_name.to_s.singularize
           end
 
-          td.primary_key pk, options.fetch(:id, :primary_key), options
+          if pk.is_a?(Array)
+            td.primary_keys pk
+          else
+            td.primary_key pk, options.fetch(:id, :primary_key), options
+          end
         end
 
         yield td if block_given?
@@ -986,6 +996,10 @@ module ActiveRecord
         [index_name, index_type, index_columns, index_options, algorithm, using]
       end
 
+      def options_include_default?(options)
+        options.include?(:default) && !(options[:null] == false && options[:default].nil?)
+      end
+
       protected
         def add_index_sort_order(option_strings, column_names, options = {})
           if options.is_a?(Hash) && order = options[:order]
@@ -1012,10 +1026,6 @@ module ActiveRecord
           column_names.map {|name| quote_column_name(name) + option_strings[name]}
         end
 
-        def options_include_default?(options)
-          options.include?(:default) && !(options[:null] == false && options[:default].nil?)
-        end
-
         def index_name_for_remove(table_name, options = {})
           index_name = index_name(table_name, options)