mongoose根据id获取上、下相邻数据详情

router.post("/bookInfo", async (ctx) => {
  let bookId = ctx.request.body.ID;
  const book = mongoose.model("book");

  // 获取上一篇和下一篇的文章
  // select是指定返回的字段
  let prevBook = await book
    .findOne({ ID: { $lt: bookId }, visible: true })
    .sort({ ID: -1 })
    .select({ ID: 1, title: 1 })
    .then((res) => res);
  let nextBook = await book
    .findOne({ ID: { $gt: bookId }, visible: true })
    .sort({ ID: 1 })
    .select({ ID: 1, title: 1 })
    .then((res) => res);
  await book
    .findOne({ ID: bookId })
    .exec()
    .then((res) => {
      ctx.body = { code: 200, message: res, prevBook, nextBook };
    })
    .catch((err) => {
      ctx.body = { code: 500, message: err };
    });
});

let boardMsgLength = await messageBoard.find({ from: "留言板" }).count(); //匹配留言板的数量
let booksMsgLength = await messageBoard  // 匹配非留言板的数量 且 根据ID查询
    .find({ from: { $ne: "留言板" }, ID: MessageBoardId })
    .count();