猫鼬找到要重命名的项目

Question

I'm trying to rename the return of some of my variables using project after a find, but it doesn't work, like this:

#Vars: email, age, name

    this.userModel.find(usersFilterQuery).project({age: 'ageUser'});

 Is it just possible? Or just using aggregate? 

Answer 1

you can create a new object after geting the model

const user = this.userModel.find(usersFilterQuery).lean();

then you can use user propreties to create your new object

const newObject = {
prop1: user.email,
prop2: user.age,
prop3: user.name
}

then

return newObject;

Answer 2

Yeah, this is not possible in find() query. So, you should use the aggregate query if you want MongoDB to do this for you:

this.userModel.aggregate([
 {
   $match: usersFilterQuery
 },
 { 
   $project: {
     age: '$ageUser'
   } 
 }
]);

---

There is more thing that you can do. You can set virtual property in your Schema model, and Mongoose will create these for you on the fly (they will not be stored in the database). So, you will tell Mongoose to add age property to each document that would be equal to the existing ageUser property.

You can check more in the official docs .