How do I query a MongoDB collection?

To query or return a MongoDB collection, use getCollection(). Let us create a collection with documents −

> db.demo294.insertOne({"EmployeeId":101,"EmployeeName":"Chris"});
{
   "acknowledged" : true,
   "insertedId" : ObjectId("5e4d4a1a5d93261e4bc9ea36")
}
> db.demo294.insertOne({"EmployeeId":102,"EmployeeName":"Bob"});
{
   "acknowledged" : true,
   "insertedId" : ObjectId("5e4d4a255d93261e4bc9ea37")
}
> db.demo294.insertOne({"EmployeeId":103,"EmployeeName":"David"});
{
   "acknowledged" : true,
   "insertedId" : ObjectId("5e4d4a335d93261e4bc9ea38")
}

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

> db.demo294.find();

This will produce the following output −

{ "_id" : ObjectId("5e4d4a1a5d93261e4bc9ea36"), "EmployeeId" : 101, "EmployeeName" : "Chris" }
{ "_id" : ObjectId("5e4d4a255d93261e4bc9ea37"), "EmployeeId" : 102, "EmployeeName" : "Bob" }
{ "_id" : ObjectId("5e4d4a335d93261e4bc9ea38"), "EmployeeId" : 103, "EmployeeName" : "David" }

Following is the query to get MongoDB collection −

> db.getCollection('demo294').find({
...   "EmployeeId":{$in:[101,103]}});

This will produce the following output −

{ "_id" : ObjectId("5e4d4a1a5d93261e4bc9ea36"), "EmployeeId" : 101, "EmployeeName" : "Chris" }
{ "_id" : ObjectId("5e4d4a335d93261e4bc9ea38"), "EmployeeId" : 103, "EmployeeName" : "David" }

AmitDiwan

Updated on 01-Apr-2020 07:12:31

• Related Questions & Answers
• How do I display the indexes of a collection in MongoDB?
• MongoDB query to rename a collection?
• How can I rename a collection in MongoDB?
• Query MongoDB collection starting with _?
• MongoDB: How to query a collection named “version”?
• MongoDB query to pull array element from a collection?
• MongoDB query to remove entire data from a collection
• MongoDB query to update a specific document from a collection
• How do I sort natural in MongoDB?
• MongoDB query to find a specific city record from a collection
• MongoDB query to find last object in collection?
• MongoDB query to remove entire array from collection?
• How do I split a numerical query result in MySQL?
• How do I change a MongoDB user's password?
• MongoDB query to add a document in an already created collection