const MongoClient = require( mongodb ).MongoClient; const url = mongodb: localhost:27017 ; Database Name const dbName = youyue ; var obj = {}; module.exports = async(ctx,next)=>{ const num = ctx.query.num, page = ctx.query.pag...

question In business, all tables in the database need to be queried and statistically analyzed and shown in the echats figure. The previous data is fine when the data is small, and the cache can barely support the column . now there is nearly 1 mi...

personal blog A personal blog written by has a concurrency problem: using Aliyun s pts to test concurrency, it is found that when the number of concurrency reaches 8 (which is negligible), the database query is particularly slow (there is very littl...

suppose I have an entity class Article @Data @Document(collection = "articles") public final class Article { @Id private String id; private String name; private String url; private String author; private List<Commen...

when using MongoRepository, I found that I want to update a field, but MongoRepository only provides the save method, but the save method requires a primary key. I directly use the default _ id as the primary key, and use the save method to insert a piec...

requirement description: mongodb contains the main information of two collection,theme storage topics, as well as an array of product id. Now if you want to find out the details of the products in products through the detailed id of the product, how sh...

I want to write a comic platform server, comics will be divided into paid and free, how should I deal with these picture resources. If I put it on oss, how can I tell whether the requesting user has paid or not? under the guidance of which god, I would b...

< H2 > for example, there are two tables < H2 > student Table id-> user id name-> user name classId-> Class id class Table id-> Class id name-> Class name if I want to query the information of all the students and the class information they b...

problem description aggregates data in a specified format into a specified format related codes { "_id" : "10.182.135.21_CPU_20180627200000", "parameter" : { "CPUUtil" : [ { ...