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node.js - 如何在 MongoDB/Mongoose 中动态添加模式

问题描述

我想创建一个由用户定义的数据库，每个用户都可以拥有自己的数据库风格。所以我使用strict: false了但是现在的问题是我不能让用户type在模型下定义每个模式

例子

const mongoose = require('mongoose');

const testSchema = new mongoose.Schema({
    label: {
        required: 'please enter label',
        trim: true,
        type: String
    },
    url: {
        type: String,
        trim: true,
    },
    settings: {}  //User defined 
    }, {
        timestamps: true, strict: false
    });


module.exports = mongoose.model('test', testSchema);

在上述情况下，我希望设置由用户定义，例如，

{
    "label": "About Us",
    "url": "www.google.com",
    "settings": { 
        "name": {
            "type": "String",   //Problem is Here, i can't send datatype directly
            "required": true
            },
        "age": {
            "type": "Number",
            "required": true,
            "enum": [10, 12]
        }
    }
}

所以请告诉我，我怎样才能让用户定义模式的类型？

标签： node.jsmongodbmongoosemongoose-schema

解决方案

strict: true并不意味着您可以将任何内容传递给settings字段。

这意味着您的架构格式是动态的 - 您可以在文档中包含未在架构中定义的意外字段名称。


回答您的问题：

好像您想要子文档，让我们制作另一个架构并将其附加为类型：

const mongoose = require('mongoose');
const Schema = mongoose.Schema;
const types = Schema.Types;

const testSettingsSchema = new Schema({
  name: {
    type: types.String,
    required: true
  },
  age: {
    type: types.Number,
    required: true
    enum: [10, 12]
  }
},
{
  _id : false,
  timestamps: false, 
  strict: false
});

const testSchema = new Schema({
  label: {
    required: 'please enter label',
    trim: true,
    type: types.String
  },
  url: {
    type: types.String,
    trim: true,
  },
  settings: {
    type: testSettingsSchema,
    required: true
  }
}, 
{
  timestamps: true, 
  strict: true
});


module.exports = mongoose.model('test', testSchema);



但是为了获得更大的灵活性并避免创建大test文档（因为用户可能会推送不可预测的大对象），请创建另一个模式：testSettings指向test_settings集合并制作settings要引用的字段：

const mongoose = require('mongoose');
const Schema = mongoose.Schema;
const types = Schema.Types;

const testSettingsSchema = new Schema({
  name: {
    type: types.Mixed
  },
  age: {
    type: types.Mixed
  }
},
{
  collection: 'test_settings',
  timestamps: false, 
  strict: false // tells to mongoose that schema may "grow"
});
mongoose.model('testSettings', testSettingsSchema);

const testSchema = new Schema({
  label: {
    required: 'please enter label',
    trim: true,
    type: types.String
  },
  url: {
    type: types.String,
    trim: true,
  },
  settings: {
    type: types.ObjectId,
    ref: 'testSettings'
    default: null
  }
}, 
{
  collection: 'tests',
  timestamps: true, 
  strict: true
});


module.exports = mongoose.model('test', testSchema);

将其创建为：

const Test = mongoose.model('test');
const TestSettings = mongoose.model('testSettings');

app.post('/tests', async (req, res) => {
  try {
    const testSettings = await TestSettings.create(req.body.settings);

    const test = new Test(req.body);
    test.settings = testSettings._id;
    await test.save();

    res.status(201).send({_id: test._id});
  }
  catch(error) {
    res.status(500).send({message: error.message});
  }
});

并在请求时间得到它：

const Test = mongoose.model('test');

app.get('/tests/:id', async (req, res) => {
  try {
    const test = await Test.findById(req.params.id)
                           .populate('settings')
                           .lean();
    res.status(200).send(test);
  }
  catch(error) {
    res.status(500).send({message: error.message});
  }
});

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