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Initial dataThe table data initialization statement is placed in the appendix of the article.Table corresponding Java entity class:public class Grade { String id; String gradeName; // The following are the properties used to associate query storage data Student student; List<Student> students; Contact contact; } ...

Basic operation of MongoDB learningThe aggregation operation of mongo is similar to the query of mysqlSQL operations / functionsmongodb aggregation operationwhere$matchgroup by$grouphaving$matchselect$projectorder by$sortlimit$limitsum()$sumcount()$sumjoin$lookupThe following examples are compared with sqlThe following is a basic structure for ...

MongoDB learning notes 01 - start MongoDB // Open service sudo service mongodb start // Start MongoDB mongo 02 - database operation command // View the database in use in the current period db // View all databases show dbs // Connect or create myTest database use myTest // Destroy myTest database use myTest db.dropDatabase() 03 - creati ...

1.mongodb official website MongoDB: the application data platform | MongoDB 2. Go to the official website of MongoDB and download MongoDB, MongoDB compass and Mongodb--database--tools 3. The operation of the MongoDB database by nodejs needs to rely on the third-party package mongoose of nodejs   Terminal instruction: npm install mongoo ...

​ ​ 1 Summary How does MongoDB implement aggregate queries? Group query? Group paging query? User defined time interval query? Time format conversion query? Don't panic. This article will introduce the implementation of grouping and aggregation query of various dimensions based on SpringBoot 2.X MongoTemplate, and catch all the complex qu ...

According to the query criteria, there are also some details to pay attention to in updating, so here we are going to update the details for your own use in the future. mongodb native db.<collection>.updateOne(filter, update, [options]); db.<collection>.updateMany(filter, update, [options]); Copy code Filter filter conditio ...

return and job management of SaltStack Experimental environment master192.168.200.142node1192.168.200.147node2192.168.200.145 1. return of saltstack component The return component can be understood as the SaltStack system stores or returns the data returned by Minion to other programs. It supports a variety of storage methods, such as MySQL, ...

1, MySQL database MySQL database notes 2, mongodb database 1, Introduction to mongodb Non relational database is a document structure, json (Dictionary Plus list), which stores large dataImmune to sql injection statement attacks. The simplest database.There are multiple libraries in mongodb. There are multiple collections in the library, an ...

MongoDB detailed syntax thinking map click here to download        With the diversified development of educational reform, school assessment methods are becoming more and more diverse. This also causes the results of the traditional course grade database table to no longer meet the setting of multiple assessm ...

MongoDB sorting / indexing / aggregation / replication / fragmentation 1, MongoDB sorting (sort() method) In MongoDB, use the sort() method to sort the data. The sort() method can specify the fields to be sorted through parameters, and use 1 and - 1 to specify the sorting method, where 1 is ascending and - 1 is descending. The basic synt ...