Stop Mongoose from creating _id property for sub-document array items

问题

If you have subdocument arrays, Mongoose automatically creates ids for each one. Example:

{
    _id: "mainId"
    subDocArray: [
      {
        _id: "unwantedId",
        field: "value"
      },
      {
        _id: "unwantedId",
        field: "value"
      }
    ]
}

Is there a way to tell Mongoose to not create ids for objects within an array?

回答1:

It's simple, you can define this in the subschema :

var mongoose = require("mongoose");

var subSchema = mongoose.Schema({
    //your subschema content
},{ _id : false });

var schema = mongoose.Schema({
    // schema content
    subSchemaCollection : [subSchema]
});

var model = mongoose.model('tablename', schema);

回答2:

You can create sub-documents without schema and avoid _id. Just add _id:false to your subdocument declaration.

var schema = new mongoose.Schema({
   field1:{type:String},
   subdocArray:[{
      _id:false,
      field :{type:String}
   }]
});

This will prevent the creation of an _id field in your subdoc. Tested in Mongoose 3.8.1

回答3:

Additionally, if you use an object literal syntax for specifying a sub-schema, you may also just add _id: false to supress it.

{
   sub: {
      property1: String,
      property2: String,
      _id: false
   }
}

回答4:

I'm using mongoose 4.6.3 and all I had to do was add _id: false in the schema, no need to make a subschema.

{
    _id: ObjectId
    subDocArray: [
      {
        _id: false,
        field: "String"
      }
    ]
}

回答5:

You can use either of the one

var subSchema = mongoose.Schema({
//subschema fields    

},{ _id : false });

var subSchema = mongoose.Schema({
//subschema content
_id : false    

});

Check your mongoose version before using the second option

来源：https://stackoverflow.com/questions/38151433/mongoose-inserts-extra-id-in-array-of-objects-corresponding-to-related-entity

标签

node.js

mongodb

mongoose

subdocument