@Override
 protected void clearCollectionParent(
     final DatabaseConnector connector, final ObjectAdapter parent) {
   // Delete collection parent
   final StringBuffer sql = new StringBuffer();
   sql.append("DELETE FROM ");
   sql.append(table);
   sql.append(" WHERE ");
   appendCollectionWhereValues(connector, parent, sql);
   connector.update(sql.toString());
 }
 protected void addColumn(
     final DatabaseConnector connection, final String columnName, final String columnType) {
   final StringBuffer sql = new StringBuffer();
   sql.append("alter table ");
   sql.append(table);
   sql.append(" add ");
   sql.append(columnName);
   sql.append(" ");
   sql.append(columnType);
   connection.update(sql.toString());
 }