--- /dev/null
+class AddUniqueIndexOnCustomFieldsTrackers < ActiveRecord::Migration
+ def up
+ table_name = "#{CustomField.table_name_prefix}custom_fields_trackers#{CustomField.table_name_suffix}"
+ duplicates = CustomField.connection.select_rows("SELECT custom_field_id, tracker_id FROM #{table_name} GROUP BY custom_field_id, tracker_id HAVING COUNT(*) > 1")
+ duplicates.each do |custom_field_id, tracker_id|
+ # Removes duplicate rows
+ CustomField.connection.execute("DELETE FROM #{table_name} WHERE custom_field_id=#{custom_field_id} AND tracker_id=#{tracker_id}")
+ # And insert one
+ CustomField.connection.execute("INSERT INTO #{table_name} (custom_field_id, tracker_id) VALUES (#{custom_field_id}, #{tracker_id})")
+ end
+
+ if index_exists? :custom_fields_trackers, [:custom_field_id, :tracker_id]
+ remove_index :custom_fields_trackers, [:custom_field_id, :tracker_id]
+ end
+ add_index :custom_fields_trackers, [:custom_field_id, :tracker_id], :unique => true
+ end
+
+ def down
+ if index_exists? :custom_fields_trackers, [:custom_field_id, :tracker_id]
+ remove_index :custom_fields_trackers, [:custom_field_id, :tracker_id]
+ end
+ add_index :custom_fields_trackers, [:custom_field_id, :tracker_id]
+ end
+end