mongoose-populate

问题 I am building an app and I have create 2 models. const UserSchema = new Schema({ _id: Schema.Types.ObjectId, account:{ type: String, unique: true }, email: String, first_name: String, last_name: String } const VenueSchema = new Schema({ _id: Schema.Types.ObjectId, venue_type: String, capacity: Number }) and const MediatorSchema = new Schema({ _id: Schema.Types.ObjectId, account:{ type: String, unique: true }, user: {type: Schema.Types.ObjectId, ref:'User' } venue: {type: Schema.Types.ObjectId

问题 I am building an app and I have create 2 models. const UserSchema = new Schema({ _id: Schema.Types.ObjectId, account:{ type: String, unique: true }, email: String, first_name: String, last_name: String } const VenueSchema = new Schema({ _id: Schema.Types.ObjectId, venue_type: String, capacity: Number }) and const MediatorSchema = new Schema({ _id: Schema.Types.ObjectId, account:{ type: String, unique: true }, user: {type: Schema.Types.ObjectId, ref:'User' } venue: {type: Schema.Types.ObjectId

问题 If a user has an array called "tags": var User = new Schema({ email: { type: String, unique: true, required: true }, tags: [{ type: mongoose.Schema.Types.ObjectId, ref:'Tag', required: true }], created: { type: Date, default: Date.now } }); and I do a populate('tags') on a query: User.findById(req.params.id) .populate("tags") .exec(function(err, user) { ... }); If one of the tags in the list has actually been deleted, is there a way to remove this dead reference in "tags"? Currently, the

问题 If a user has an array called "tags": var User = new Schema({ email: { type: String, unique: true, required: true }, tags: [{ type: mongoose.Schema.Types.ObjectId, ref:'Tag', required: true }], created: { type: Date, default: Date.now } }); and I do a populate('tags') on a query: User.findById(req.params.id) .populate("tags") .exec(function(err, user) { ... }); If one of the tags in the list has actually been deleted, is there a way to remove this dead reference in "tags"? Currently, the

问题 I have the following mongoose schema structure userSchema = new Schema({ roles: [ role: {type: Schema.Types.ObjectId, ref: 'Role' } ] }) rolesSchema = new Schema({ name: String, roleEntities: [ { entity : {type: Schema.Types.ObjectId, ref: 'RoleEntity' }, abilities : [{type: Schema.Types.ObjectId, ref: 'Ability' }] } ] } roleEntitiesSchema = new Schema({ name: String }) abilitiesSchema = new Schema({ name: String }) How can i populate all these nested documents while doing a find on the USER

问题 I have the following mongoose schema structure userSchema = new Schema({ roles: [ role: {type: Schema.Types.ObjectId, ref: 'Role' } ] }) rolesSchema = new Schema({ name: String, roleEntities: [ { entity : {type: Schema.Types.ObjectId, ref: 'RoleEntity' }, abilities : [{type: Schema.Types.ObjectId, ref: 'Ability' }] } ] } roleEntitiesSchema = new Schema({ name: String }) abilitiesSchema = new Schema({ name: String }) How can i populate all these nested documents while doing a find on the USER

问题 In the user model, I have an array of custom objects followedPlaylists which contains two attributes ( playlist: the id of the playlist, public: to determine whether it is public or not) as shown below const userSchema = new mongoose.Schema({ ..... other attributes followedPlaylists: [{ playlist: { type: mongoose.Schema.ObjectId, ref: 'Playlist', unique: true }, public: Boolean }] }) I want to populate on followedPlaylists.playlist so the response would be something like [{ playlist: * the

问题 Consider the code below: const aux = await Fasta.find({}, "healthyTissue") .limit(1) .populate({ //---------------------first level (healthy or tumor fasta file) ---------------- path: "healthyTissue", model: "Hidden", options: { limit: 2 }, //--------------------- second level (hidden documents) ---------------- populate: { path: "children", options: { limit: 2 }, model: "FastaElement" } }); This is the output: The problem: just the first children is populated . I have double-checked the

问题 I have a node app that uses 2 databases. One is the the Names and the other for the rest of all the data. I have this connection setup: // DATABASE CONNECTION var APP_DB_URI = config.APP_DB; // mongodb://localhost:27017/app_db var app_DB = mongoose.createConnection(APP_DB_URI); var name_DB = app_DB.useDb(config.NAME_DB); // 'name_db' This connection is working properly. There's also no problem upon saving data to both app_db and names_db working perfect. But the problem is this: when I try to

问题 I have a query like this: galleryModel.find({_id: galleryId}) .populate({ model: 'User', path: 'objectId', select: 'firstName lastName' }) End response for objectId will be like this: objectId: { ... } How can I change it to user in response without changing real path? 回答1: You can do this by virtual populate, introduced in mongoose version 4.5 . For that you need to define a virtual field in mongoose schema. var GallerySchema = new mongoose.Schema({ name: String, objectId: { type: mongoose