Question

我正在使用MongoDB在NodeJS中开发一个演示应用程序，目前使用的模块是Express和Mongoose。

主要思想是重制一个PHP + MySQL应用程序，其中MySQL数据库由三个表组成，关于1：N关系：Company-＆gt; Field-＆gt; Item

示例数据收集如下所示：

[
{"id": 1,"name": "DemoCompanyOne", "fields":[
    {"id": 1, "location": "DemoLocationOne", "items":[
        {"_id": 1,"name": "DemoItemOne","price": 1500,"count": 16,"date": "2013-11-02 16:53:19"}, 
        {"_id": 2,"name": "DemoItemTwo","price": 890,"count": 211,"date": "2013-11-02 16:53:19"}
    ]}, 
    {"id": 2, "location": "DemoLocationTwo", "items":[
        {"_id": 3,"name": "DemoItemThree","price": 9990,"count": 10,"date": "2013-11-02 19:12:40"}, 
        {"_id": 4,"name": "DemoItemFour","price": 2500,"count": 20,"date": "2013-11-02 19:12:42"}
    ]}
]}, 
{"id": 2,"name": "DemoCompanyTwo", "fields":[
    {"id": 3, "location": "DemoLocationThree", "items":[
        {"_id": 5,"name": "DemoItemFive","price": 79000,"count": 11,"date": "2013-11-02 16:56:13"}, 
        {"_id": 6,"name": "DemoItemSix","price": 649,"count": 8760,"date": "2013-11-02 16:56:13"}, 
        {"_id": 7,"name": "DemoItemSeven","price": 149,"count": 4320,"date": "2013-11-02 16:57:19"}
    ]}
]}
]

我在Mongoose制定了计划，如：

var Schema = mongoose.Schema, ObjectId = Schema.ObjectId

var Items = new Schema({
    _id: ObjectId,
    name: String,
    price: Number,
    count: Number,
    date: { type: Date, default: Date.now }
});

var Field = new Schema({
    id: Number,
    location: String,
    items: [Items]
});

var Company = new Schema({
    id: Number,
    name: String,
    Fields: [Field]
});

var cmp = mongoose.model('company', Company, "company");
var flds = mongoose.model('fields', Field, "fields");
var itm = mongoose.model('items', Items, "items");

请注意，项目的_id已更改为Mongo中的ObjectId，因为我希望这可以帮助我更好地处理这些嵌入式集合 - 它没有。

我想将项目插入指定的位置，或者增加所选项目的计数，或删除所选项目。

company_id和field_id包含在网址中，如下：

app.post('/:company_id/:field_id', function(req, res) { ... })

在此处理程序中，我将请求分开，例如：

app.post('/:company_id/:field_id', function(req, res) {
var company = req.params.company_id;
var field = req.params.field_id;
if (req.body.new != null)
{
    cmp.findOne({}).where('id').equals(company).where('fields.id').equals(field).exec(function(err, comps) {
        if (comps == null)
        { res.render('error', {title: 'Error!', msg: 'No such field!'}); }
        else
        { 
            i=0;
            while (i < comps.fields.length && comps.fields[i].id != field)
            { i++; }
            var r = new itm({"_id": "", "name": req.body.name, "price":req.body.price, "count":req.body.count});
            comps.fields[i].items.push(r);
            comps.save();
        }
    });
}
else if (req.body.mod != null)
{
    //...
}
else if (req.body.del != null)
{
    //...
}
res.redirect('/'+company+'/'+field);
})

如你所见，在项目添加上我使用线性搜索来查找字段，我可以在那里推送新制作的项目...这非常非常难看，我确信必须有更简单的方法这样做......

那么，增量还是去除呢？我不想以同样的方式......

而且，对于第四个问题：您如何看待ID？如何实施？我应该在任何地方使用ObjectIds，还是根本不需要它？

感谢任何帮助和想法！

Answer 1

我的愿景是，如果它们几乎是静态的，您可以使用嵌入式文档。你的对象看起来很动态，所以我建议你尝试使用文档引用：

var Schema = mongoose.Schema, ObjectId = Schema.ObjectId

var Items = new Schema({
    _id: ObjectId,
    name: String,
    price: Number,
    count: Number,
    date: { type: Date, default: Date.now }
    field: {type: Schema.Types.ObjectId, ref: 'Field'}
});

var Field = new Schema({
    id: Number,
    location: String,
    company: {type: Schema.Types.ObjectId, ref: 'Company'}
    items: [{type: Schema.Types.ObjectId, ref: 'Items'}]
});

var Company = new Schema({
    id: Number,
    name: String,
    fields: [{type: Schema.Types.ObjectId, ref: 'Field'}]
});

所以你保留像MySQL这样的父引用+将子引用作为一个数组来快速填充。因此，您不必弄乱嵌套文档：

Field.findOne({_id: fieldid}).exec(function(err, field){...do whatever you need...})

此外，我不建议将您的模型称为“项目”。用单数称它，比如“Item”。

使用Mongoose从Node中插入，更新和删除MongoDB中的复杂嵌入式集合

1 个答案: