Make sure that the Schema Dumper supports non-standard primary keys with MySQL. Closes #9971 [RubyRedRick]

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@8012 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

1 files changed, 10 insertions, 0 deletions

diff --git a/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb b/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
index 65faa80065..5242151736 100755
--- a/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
@@ -440,6 +440,16 @@ module ActiveRecord
         variables.first['Value'] unless variables.empty?
       end
 
+      # Returns a table's primary key and belonging sequence.
+      def pk_and_sequence_for(table) #:nodoc:
+        table_desc_result = execute("describe #{table}")
+        keys = []
+        execute("describe #{table}").each_hash do |h|
+          keys << h["Field"]if h["Key"] == "PRI"
+        end
+        keys.length == 1 ? [keys.first, nil] : nil
+      end
+
       private
         def connect
           encoding = @config[:encoding]