MongoDB中获取特定的多个文档

要在MongoDB中获取特定的多个文档，请使用$in。让我们使用文档创建一个集合-> db.demo593.insertOne({id:1,"Name":"Chris"});{ "acknowledged" : true, "insertedId" : ObjectId("5e93177dfd2d90c177b5bcd9") } > db.demo593.insertOne({id:2,"Name":"John"});{ "acknowledged" : true, "insertedId" : ObjectId("5e931785fd2d90c177b5bcda") } > db.demo593.insertOne({id:3,"Name":"Bob"});{ "acknowledged" : true, "insertedId" : ObjectId("5e93178cfd2d90c177b5bcdb") } > db.demo593.insertOne({id:4,"Name":"Sam"});{ "acknowledged" : true, "insertedId" : ObjectId("5e931792fd2d90c177b5bcdc") }

在find()方法的帮助下显示集合中的所有文档-

> db.demo593.find();

这将产生以下输出-

{ "_id" : ObjectId("5e93177dfd2d90c177b5bcd9"), "id" : 1, "Name" : "Chris" } { "_id" : ObjectId("5e931785fd2d90c177b5bcda"), "id" : 2, "Name" : "John" } { "_id" : ObjectId("5e93178cfd2d90c177b5bcdb"), "id" : 3, "Name" : "Bob" } { "_id" : ObjectId("5e931792fd2d90c177b5bcdc"), "id" : 4, "Name" : "Sam" }

以下是获取特定多个文档的查询-

> db.demo593.find({id:{$in:[1,3]}});

这将产生以下输出-

{ "_id" : ObjectId("5e93177dfd2d90c177b5bcd9"), "id" : 1, "Name" : "Chris" } { "_id" : ObjectId("5e93178cfd2d90c177b5bcdb"), "id" : 3, "Name" : "Bob" }