这是使用 mongoose 在 MongoDB 中查询的正确方法吗

Question

const {email, username} = req.body
const userExistsbyEmail = User.findOne({
 $and: [{ _id: { $ne: req.params.id } }, { email }],
})
const userExistsbyUsername = User.findOne({
 $and: [{ _id: { $ne: req.params.id } }, { username }],
})

if (userExistsbyEmail || userExistsbyUsername) {
 res.status(400)
 throw new Error('User already exists')
}

I want to get the details of username and email during updating the userprofile , if there is then it show throw an error?

Thank you

Answer 1

First of all, if you want to thrown an error when username or email exists I think the best way is set your variables as unique in you schema.

Something like this:

const model = new moongose.Schema({
  username:{
    type: String,
    unique: true
  },
  email:{
    type: String,
    unique: true
  }
})

Then, when you try to insert a document with the same value it will thrown an error:

E11000 duplicate key error dup key: { : "key" }

Also, if you need or you want a query then you can use something like this:

db.collection.find({
  "$or": [
    {
      "username": "user"
    },
    {
      "email": "mail"
    }
  ]
})

Example here .

With this query if exists the username or email it will return the document, and then you can check if count is greater than 0 or whatever you want.