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This time I will bring you the steps to implement aggregate cascade query. What are the precautions for implementing aggregate cascade query? The following is a practical case, let's take a look.
I recently completed a nodejs mongoose project and encountered the cascade query operation of Account table: Company information exists in a separate account table.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 table: The company’s customer base.
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 table
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);What we need to do here is to organize and sort the soft articles by accountId→aggregate→cascade author to find the author's name and other information. The code is as follows:
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); })); }) }); };The returned result format (there are only two records here, actually the top ten):
[ { _id: { customerId: 559a5b6f51a446602032fs21 }, number: 5, customerName: 'test2', mobile:22 } , { _id: { customerId: 559a5b6f51a446602041ee6f }, number: 1, customerName: 'test1', mobile: 11 } ]I believe you have mastered it after reading the case in this article Method, for more exciting information, please pay attention to other related articles on the php Chinese website! Recommended reading:
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