Add unique index on tokens.value.

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@11295 e93f8b46-1217-0410-a6f0-8f06a7374b81

db/migrate/20130201184705_add_unique_index_on_tokens_value.rb

@@ -0,0 +1,15 @@
+class AddUniqueIndexOnTokensValue < ActiveRecord::Migration
+  def up
+    say_with_time "Adding unique index on tokens, this may take some time..." do
+      # Just in case
+      duplicates = Token.connection.select_values("SELECT value FROM #{Token.table_name} GROUP BY value HAVING COUNT(id) > 1")
+      Token.where(:value => duplicates).delete_all
+  
+      add_index :tokens, :value, :unique => true, :name => 'tokens_value'
+    end
+  end
+
+  def down
+    remove_index :tokens, :name => 'tokens_value'
+  end
+end