Question

虽然有很多答案说明了如何使用.populate填充特定字段，但我想知道是否可以在queryOptions的populate字段中进行相同的操作？

例如，如果我的模式是：

AuthorSchema = new mongoose.Schema({
  name: String
  nationality: String,
  dateOfBirth: Date
});

BookSchema = new mongoose.Schema({
  title: String,
  author: { type: mongoose.Schema.Types.ObjectId, ref: 'Author' }
});

查询内容如下：

  const queryOptions = {
    limit: limit,
    skip: skip,
    populate: [{
      author: { name: 1 }
    }]
  };

  const books = await Book.find(query, null, queryOptions);

可以通过这种方式实现吗？

顺便说一句假定猫鼬5.6.7 +。

Answer 1

尝试这个例子。

const mongoose = require('mongoose')
const Schema = mongoose.Schema
mongoose.connect("mongodb://localhost/stack-overflow", { useNewUrlParser: true })

const AuthorSchema = new mongoose.Schema({
    name: String,
    nationality: String,
    dateOfBirth: { type: Date, default: Date.now }
});
const Author = mongoose.model("Author", AuthorSchema)

const BookSchema = new mongoose.Schema({
  title: String,
  author: { type: mongoose.Schema.Types.ObjectId, ref: 'Author' }
});
const Book = mongoose.model("Book", BookSchema)

Book.
find({}).
populate("author",{name: 1}).
skip(0).
limit(1).
exec().
then(books => {
    console.log("books", books)
}).catch(err => {
    console.log(err)
})

猫鼬并在填充queryOptions期间选择特定字段？

1 个答案: