Question

我正在尝试根据填充的子文档获取文档。

这是我的模特

// User model

    var UserSchema = new mongoose.Schema({
     username: {type: String, required: true, trim: true},
     firstName: {type: String, required: true, lowercase: true},
     lastName: {type: String, required: true, lowercase: true},
     phone: {type: String, required: false},
     email: {type: String, required: true},
     password: {type: String, required: true},
     blogs: {type: mongoose.Schema.Types.ObjectId, ref: 'Blogs'}
    }, {timestamps: true});


// Blog Model

    var BlogSchema = new mongoose.Schema({
     description: String,
     tags: [String],
     other: [Object],
    }, {timestamps: true});

这就是我抓取文件的方式

  fetchAllByFilter: async function(req, res) {
      try {
          let result = await Users.find({}).populate('blog');
          return res.status(200).send(result);
      }  catch (err) {
          return res.status(200).send({error: err});
      }
    },

现在我的主要问题是，如何根据用户的Blog引用文档来抓住用户？

例如，查找具有Blog.tags为“ {food”，“汽车”，“电影”和/或Blog.other为[{...SomeObject}, {...SomeOtherObject}]的Blog的用户

Answer 1

查看mongo docs match an array，您可以使某个实用程序功能如下...

async function findByTag(tag) {
    const blogIds = await Blog.find({ tags: tag }).select("_id");

    const users = await User.find({
        blogs: { $in: blogIds.map((blog) => blog._id) }
    }).populate("blog");
}

如何基于参考填充子文档在mongodb上过滤文档？

1 个答案: