docs: @SuppressWarnings("unchecked")
      public <N extends Object> List<N> findOneColumn(String sql, List<?> params, final int mapperColumnIndex) {
  
          if (sql == null) {
              recordLog(" param sql is null!");
          }
  
          // 查询
          return findBySQL(sql, params, new RowMapper<N>() {
              public N mapRow(ResultSet rs, int count) throws SQLException {
                  return (N) (rs.getObject(mapperColumnIndex));
              }
          });
      }