如何制定以下Mongoose查询?

时间:2013-08-15 14:00:32

标签: mongodb mongoose mongoose-populate

这是我的架构:

var A = new Schema({
    active: Boolean
  , containers: [{
         b: { type: ObjectId, ref: 'B' }
    }]
})

var B = new Schema({
    c: { type: ObjectId, ref: 'C' }
  , d: { type: ObjectId, ref: 'D' }
})

var C = new Schema({ })

var D = new Schema({ })

基本上A有一组容器,其引用BB引用CD }。

现在我有一个C的ID,我需要D active使用的一组A。这甚至可能吗?我应该以某种方式更改架构吗?

编辑:这里的真实架构

 //Mashup has a number of Containers (containerSchema is a sub-doc)
    //so that the same Component could belong to two different Containers
    var containerSchema = new Schema({
          pos: { top: Number, left: Number }
        , size: { width: Number, height: Number }
        , component: { type: ObjectId, ref: 'Component' }
    })

    var mashupSchema = new Schema({
          name: String
        , desc: String
        , size: { width: Number, height: Number }
        , active: Boolean
        , containers: [containerSchema]
    })

    //I am using 'mongoose-schema-extend' to inherit from componentSchema (waiting for the new PR)
    var componentSchema = new Schema({
          name: String
        , desc: String
    }, { collection : 'components', discriminatorKey : '_type' })

    //now the various components
    var imageComponentSchema = componentSchema.extend({
          url: String
    })

    var textComponentSchema = componentSchema.extend({
          text: String
    })


    var htmlComponentSchema = componentSchema.extend({
          html: String
    })

    //this particular component needs a page and a selector
    //(which could live outside it and belong to multiple components)
    var webComponentSchema = componentSchema.extend({
          page: { type: ObjectId, ref: 'Page' }
        , selector: { type: ObjectId, ref: 'Selector' }
    })

    var pageSchema = new Schema({
          name: String
        , desc: String
        , url: String
        , active: { type: Boolean, default: false }
    })

    var selectorSchema = new Schema({
          desc: String
        , url: String
        , cssPath: String
    })

    ///MODELS
    var Mashup = mongoose.model("Mashup", mashupSchema)
    var Component = mongoose.model("Component", componentSchema)
    var ImageComponent = mongoose.model("ImageComponent", imageComponentSchema)
    var TextComponent = mongoose.model("TextComponent", textComponentSchema)
    var HtmlComponent = mongoose.model("HtmlComponent", htmlComponentSchema)
    var WebComponent = mongoose.model("WebComponent", webComponentSchema)
    var Page = mongoose.model("Page", pageSchema)
    var Selector = mongoose.model("Selector", selectorSchema)

2 个答案:

答案 0 :(得分:1)

你认为太关系了!现在你,我认为你不能有效地做到这一点,因为你必须:

  • 找到所有包含c: {id}
  • 的B
  • 查找所有具有b的A,即查询1 的结果集合
  • 找出哪些B属于您在上一个查询中找到的ID
  • 找出哪些D属于您找到的B

我认为你最应该在这里对你的架构进行非规范化。例如,您可以将以上所有内容放在一个文档中:

{
    Active: true,
    containers: [ // B's
        { c: [
            { _id: X, field1: foo },
            { _id: X, field1: foo },
        ] },
        { d: [
            { _id: X, field1: foo },
            { _id: X, field1: foo },
        ] }
    ]
}

然后你可以用一个查询来做到这一点:

db.collection.find(
    { "container.c._id" : your_id, Active: true }, // query
    { "container.d" : 1 } // projection
);

答案 1 :(得分:0)

完全更改数据库架构。闭。