code: public int update(String sql, Object param) throws SQLException {
          return this.update(sql, new Object[] { param });
      }
docs: Executes the given INSERT, UPDATE, or DELETE SQL statement with
  a single replacement parameter.  The <code>Connection</code> is
  retrieved from the <code>DataSource</code> set in the constructor.
  This <code>Connection</code> must be in auto-commit mode or the
  update will not be saved.
  
  @param sql The SQL statement to execute.
  @param param The replacement parameter.
  @throws java.sql.SQLException if a database access error occurs
  @return The number of rows updated.