I have an Order model:

const orderSchema = new mongoose.Schema({
 order_items: [{
  type: mongoose.Schema.Types.ObjectId,
  ref: 'OrderItem',
  required: true
 }],
 user: {
  type: mongoose.Schema.Types.ObjectId,
  ref: 'User',
  required: true
 },
 shipping_address: {
  type: String,
  required: true
 },
 total_price: {
  type: Number
 }
});

And OrderItem model:

const orderItemSchema = new mongoose.Schema({
 product_id: {
  type: mongoose.Schema.Types.ObjectId,
  ref: 'Product',
  required: true
 },
 quantity: {
  type: Number,
  required: true
 },
 unit_price: {
  type: Number,
  required: true
 }
});

And Product model:

const productSchema = new mongoose.Schema({
 name: {
  type: Map,
  of: String,
  required: true
 },
 unit_price: {
  type: Number,
  required: true
 }
});

I tried to do double populate on find Order in the request like this:

const findOrder = await Order.find({ user: user_id }).populate('order_items').populate({ path: 'order_items.product_id', select: 'name' });

But I get only the first populate. When I tried the following:

const findOrder = await Order.find({ user: user_id }).populate('order_items').populate({ path: 'product_id', select: 'name' });

I got this error:

Cannot populate path product_id because it is not in your schema. Set the strictPopulate option to false to override.

How can I get the product's name in a nested populate request?

Thanks...

CodePudding user response：

Try with:

const findOrder = await Order.find({ user: user_id })
  .populate({
    path: 'order_items',
    populate: {
        path: 'product_id',
        select: 'name'
    } 
  }).exec();

For more information about the population across multiple levels read here.