我正在NodeJS中开发一个使用MongoDB的演示应用程序,目前使用的模块是Express和Mongoose。
主要想法是重新构建一个PHP+MySQL应用程序,其中MySQL数据库由三个表组成,关系为1:N:Company->Field->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中制定了一些方案,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,在Mongo中,items的_id被更改为ObjectId,因为我希望这能帮助我更好地处理这些嵌入的集合,但事实并非如此。
我希望将项目插入指定位置,或增加所选项目的计数,或删除所选项目。
company_id和field_id包含在URL中,如下所示:
app.post('/:company_id/:field_id', function(req, res) { ... })
在这个处理程序中,我分离请求,比如:
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);
})
正如你所看到的,在添加项目时,我使用线性搜索来找到字段,在那里我可以推送新制作的项目。。。这非常非常丑陋,我相信一定有更简单的方法。。。
那么,增加还是删除呢?我不想以同样的方式。。。
第四个问题是:你觉得身份证怎么样?如何实施?我应该在任何地方使用ObjectId,还是在任何地方都不需要?
感谢您的帮助和想法!
我的设想是,如果嵌入式文档几乎是静态的,那么就使用它们。您的对象在我看来是动态的,所以我建议您尝试使用文档引用:
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'}]
});
因此,您可以像在MySQL中那样保留父引用,并将子引用作为数组来快速填充。因此,您不必处理嵌套文档:
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"。用单数来称呼它,比如"Item"。