mongoose - 设置外键引用的表示

I'm developing an REST API for mobile app, This is part of model i'm using

我正在为移动应用程序开发REST API,这是我正在使用的模型的一部分

var UserSchema = new Schema(
{
    email : 
    {
        type : String, 
        unique : true
    },
    login_type : String,
    username : 
    {
        type : String,
        index : true
    },
    password : String
}

And I added user's oid to post schema as reference

我添加了用户的oid作为参考发布模式

var PostSchema = new Schema(
{
    author : {type : Schema.Types.ObjectId, ref : "User"},
    board_id : {type : Schema.Types.ObjectId, ref : "Board"},
    regDate : Number,
    lastModDate : Number,
    title : String,
    content : String,
}

so, the posts can reference user collections to get username of user who posted it. So i want to get just username of user, others are not necessary. For this, i used follows.

所以,帖子可以引用用户集合来获取发布它的用户的用户名。所以我想获得用户的用户名,其他人则没有必要。为此,我用了以下。

var query = Post.find({"regDate" :{$lte : before}},
{
    _id : 1,
    title : 1,
    "author.username" : 1,
    regDate : 1
})

but the mongoose ignored that "author.username". How can i get just username of author, not all?

但是猫鼬忽略了“author.username”。我怎样才能获得作者的用户名,而不是全部?

1 个解决方案

#1

You should use populate function and enumerate selected fields there:

你应该使用populate函数并枚举那里的选定字段:

Post
    .find({ regDate :{ $lte : before }}, 'title reqDate')
    .populate('author', 'username')
    .exec();