Following is the syntax to count the number of documents in a MongoDB collection
let anyVariableName= db.getCollection(‘yourCollectionName’); yourVariableName.count();
Let us first create a collection with documents
> db.countNumberOfDocumentsDemo.insertOne({"CustomerName":"Bob"}); { "acknowledged" : true, "insertedId" : ObjectId("5c9a5e2015e86fd1496b38a1") } >db.countNumberOfDocumentsDemo.insertOne({"CustomerName":"Ramit","CustomerAge":23}); { "acknowledged" : true, "insertedId" : ObjectId("5c9a5e3515e86fd1496b38a2") } >db.countNumberOfDocumentsDemo.insertOne({"CustomerName":"Adam","CustomerAge":27,"CustomerCountryName":"US"}); { "acknowledged" : true, "insertedId" : ObjectId("5c9a5e4c15e86fd1496b38a3") }
Following is the query to display all documents from a collection with the help of find() method
> db.countNumberOfDocumentsDemo.find().pretty();
This will produce the following output
{ "_id" : ObjectId("5c9a5e2015e86fd1496b38a1"), "CustomerName" : "Bob" } { "_id" : ObjectId("5c9a5e3515e86fd1496b38a2"), "CustomerName" : "Ramit", "CustomerAge" : 23 } { "_id" : ObjectId("5c9a5e4c15e86fd1496b38a3"), "CustomerName" : "Adam", "CustomerAge" : 27, "CustomerCountryName" : "US" }
Following is the query to count the number of documents in a MongoDB collection,
> let myCollectionName = db.getCollection('countNumberOfDocumentsDemo'); > myCollectionName.count();
This will produce the following output
3