code: public int update(Connection conn, String sql) throws SQLException {
          return this.update(conn, sql, (Object[]) null);
      }
docs: Execute an SQL INSERT, UPDATE, or DELETE query without replacement
  parameters.
  
  @param conn The connection to use to run the query.
  @param sql The SQL to execute.
  @return The number of rows updated.
  @throws java.sql.SQLException if a database access error occurs