Mongodb 未读标志未使用Mongoose更新

我的数据库中有一个

conversations

集合，我正在使用Mongoose更新单个文档的

unread

标志

这是我的代码：

router.post('/reply/:conversation_id', ensureAuthenticated, (req, res, next) => {
  Conversation.findById(req.params.conversation_id, (err, conversation) => {

    // If the user that's logged in was the one who created the conversation, and is submitting a reply, run this code
    if (req.user._id == conversation.created_by_user_id) {
      User.findById(conversation.sent_to_user_id, (err, user) => {
        Message.create({
          //...
        }, (err, message) => {
          if (err) {
            console.log(err)
          } else {
            message.conversations.push(conversation._id)
            conversation.unread = true
            conversation.save()  // This is being saved to the database
            message.save()
            res.redirect('/conversations/' + conversation._id)
          }
        })
      })
    } else {
    // Otherwise, if the user that's logged in was *not* the one who created the conversation, and is submitting a reply, run this code

      User.findById(conversation.created_by_user_id, (err, user) => {
        Message.create({
          //...
        }, (err, message) => {
          if (err) {
            console.log(err)
          } else {
            message.conversations.push(conversation._id)
            conversation.unread = true
            conversation.save() // This is not being saved
            message.save()
            res.redirect('/conversations/' + conversation._id)
          }
        })
      })
    }
  })
});

if

部分将

conversation.unread=true

保存到数据库。

else

部件不可用

条件的两个部分基本上做相同的事情（将对话的

未读

标记保存为

真

，并保存消息），但只有条件的第一部分在将

未读

设置为真时起作用

---

有人能帮我弄清楚为什么

未读

标记没有在

其他

语句中保存为

真

。

您正在尝试同步调用

保存

.save

接受回调。它是异步的

请参阅下面的我的版本

router.post('/reply/:conversation_id', ensureAuthenticated, (req, res, next) => {
  Conversation.findById(req.params.conversation_id, (err, conversation) => {

    // If the user that's logged in was the one who created the conversation, and is submitting a reply, run this code
    if (req.user._id == conversation.created_by_user_id) {
      User.findById(conversation.sent_to_user_id, (err, user) => {
        Message.create({
          //...
        }, (err, message) => {
          if (err) {
            console.log(err)
          } else {
            message.conversations.push(conversation._id)
            conversation.unread = true
            conversation.save()  // This is being saved to the database
            message.save()
            res.redirect('/conversations/' + conversation._id)
          }
        })
      })
    } else {
    // Otherwise, if the user that's logged in was *not* the one who created the conversation, and is submitting a reply, run this code

    User.findById(conversation.created_by_user_id, (err, user) => {
      Message.create({
          //...
        }, (err, message) => {
          if (err) {
            console.log(err)

            //return here
            return res.redirect('/error'); //

          } else {
            message.conversations.push(conversation._id)
            conversation.unread = true

            //.save takes a function callback
            conversation.save((err) => {

              //.save takes a function callback
              message.save((err) => {
                res.redirect('/conversations/' + conversation._id)
              })
            })
          }
        })
    })
  }
})
});