Fetch specific multiple documents in MongoDB

To fetch specific multiple documents in MongoDB, use $in. Let us create a collection with documents −

> 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")
}

Display all documents from a collection with the help of find() method −

> db.demo593.find();

This will produce the following output −

{ "_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" }

Following is the query to fetch specific multiple documents −

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

This will produce the following output −

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

AmitDiwan

Published on 15-May-2020 10:25:54