mongodb aggregate 级联查询

最近完成了一个nodejs+mongoose的项目，碰到了mongodb的级联查询操作。情形是实现一个排行榜，查看某个公司（organization）下属客户中发表有效文ruan章wen最多的前十人。

Account表：公司的信息单独存在一个account表里。

var AccountSchema = new Schema({
    loginname: {type: String},
    password: {type: String},
    /** * 联系方式 */
    //账户公司名
    comName: {type: String},
    //地址
    address: {type: String},
    //公司介绍
    intro: {type: String}
    });

    mongoose.model('Account', AccountSchema);

Cusomer表：公司的客户群。

var CustomerSchema = new Schema({
    /** * 基本信息 */
    //密码
    password: {type: String},
    //归属于哪个Account
    belongToAccount: {type: ObjectId, ref: 'Account'},
    //手机号，登录用
    mobile: {type: String},
    //真实姓名
    realname: {type: String}

    });
    CustomerSchema.index({belongToAccount: 1, mobile: 1}, {unique: true});
    mongoose.model('Customer', CustomerSchema);

article表

var articleSchema= new Schema({
    belongToAccount: {type: ObjectId, ref: 'Account'},

    title: {type: String},
    text: {type: String},
    createTime: {type: Date, default: Date.now},
    author: {type: ObjectId, ref: 'Customer'},

    //0,待确认,1 有效 ,-1 无效
    status: {type: Number, default: 0}
});

articleSchema.index({belongToAccount: 1, createTime:-1,author: 1}, {unique: false});
mongoose.model('article', articleSchema);

这里要做的就是，由accountId→aggregate整理软文并排序→级联author找到作者的姓名及其他信息。

代码如下：

exports.getRankList = function (accountid, callback) {
    AticleModel.aggregate(
        {$match: {belongToAccount: mongoose.Types.ObjectId(accountid), status: 1}},
        {$group: {_id: {customerId: "$author"}, number: {$sum: 1}}},
        {$sort: {number: -1}}).limit(10).exec(function (err, aggregateResult) {
        if(err){
            callback(err);
            return;
        }
            var ep = new EventProxy();
            ep.after('got_customer', aggregateResult.length, function (customerList) {
                callback(null, customerList);
            });
              aggregateResult.forEach(function (item) {
                Customer.findOne({_id: item._id.customerId}, ep.done(function (customer) {
                    item.customerName = customer.realname;
                    item.customerMobile=cusomer.mobile; 
                    // do someting 
                    ep.emit('got_customer', item);
                }));
            })
        });
};

返回的结果格式（这里仅有两条记录，实际为前十）：

[ { _id: { customerId: 559a5b6f51a446602032fs21 }, number: 5,
customerName: ‘test2’,
mobile:22 } ，
{ _id: { customerId: 559a5b6f51a446602041ee6f }, number: 1,
customerName: ‘test1’,
mobile: 11 } ]