Mongoose update without callback

问题:

I have a typical schema and model:

var mongoose = require('mongoose');

var userSchema = new mongoose.Schema({
    email: String,
    password: String,
    profile: {
        name: String,
        surname: String,
        photo: String
    },
    stats: {
        lastLogin: { type: Date, default: Date.now },
        loginCount: Number,
        lastIP: String
    },
    source: String,
    deleted: Boolean,
    dateCreated: { type: Date, default: Date.now }
});

mongoose.model('User', userSchema);

When I perform this update, it only works if I define the callback, else it simply executes but no value is changed in the database:

User.update({email:'[e-mail]'}, {$inc: {'stats.loginCount': 1}});

This works:

User.update({email:'[e-mail]'}, {$inc: {'stats.loginCount': 1}}, function() {});

Is this a bug? I don't see in the documentation if the callback is required but it's strange to require this… I think i'm missing something here.

Notes: I'm matching by email for testing proposes, I'm using mongoose v3.5.4 in NodeJS v0.8.17 with a simple Express v3.0.6 setup.

Thanks in advance.

回答1:

The right way to call update with mongoose is the following:

User.update(query, update).exec(callback);

This way you will be able to skip callback:

User.update(query, update).exec();

When you calls

User.update(query, update)

it returns a query object.

It's very useful when you querying your database, because you can manipulate with query object before executing it. For example, you can specify a limit for your find query:

User.find(query).limit(12).exec(callback);

Update uses the same mechanism, though its not so useful there.