在两个文档中都找到条件的嵌入式文档

Question

I am developing an program with 2 models, building and floor. The schema are defined as following.

var BuildingSchema = new Schema({
    block:{type:String,trim:true},
    project_id:{type:String},
    floors:[{type:Schema.Types.ObjectId,ref:'Floor'}]
})

var FloorSchema = new Schema({
    name:{type:String,trim:true},
    building_id:{type:String,ref:'Building'}
}

What I would like to do is to find the floor result with the conditions of floor.name and building.project_id. I have tried this but didn't work

floor.find({name:'fname','building_id.project_id':123}).exec()

How do I get what I want? Thanks.

Answer 1

You'll need to make use of $elemMatch to retrieve just the floor. The mongoosejs docs talk about it here .

So you might do something like:

building.find({"project_id": 123}).where("floors").elemMatch(function(elem){
  elem.match("name", "fname");
});

This should only return the floor element that matches {"name": "fname"}