Let us first create a collection with documents −
> db.excludeIdDemo.insertOne({"StudentFirstName":"John","StudentAge":21}); { "acknowledged" : true, "insertedId" : ObjectId("5cd701a56d78f205348bc632") } > db.excludeIdDemo.insertOne({"StudentFirstName":"Robert","StudentAge":20}); { "acknowledged" : true, "insertedId" : ObjectId("5cd701af6d78f205348bc633") } > db.excludeIdDemo.insertOne({"StudentFirstName":"Chris","StudentAge":24}); { "acknowledged" : true, "insertedId" : ObjectId("5cd701b86d78f205348bc634") }
Following is the query to display all documents from a collection with the help of find() method −
> db.excludeIdDemo.find();
This will produce the following output −
{ "_id" : ObjectId("5cd701a56d78f205348bc632"), "StudentFirstName" : "John", "StudentAge" : 21 } { "_id" : ObjectId("5cd701af6d78f205348bc633"), "StudentFirstName" : "Robert", "StudentAge" : 20 } { "_id" : ObjectId("5cd701b86d78f205348bc634"), "StudentFirstName" : "Chris", "StudentAge" : 24 }
Following is the query to exclude _id without including other fields using the aggregation framework −
> db.excludeIdDemo.aggregate( { $project : { _id : 0, "StudentFirstName": 1 } } );
This will produce the following output −
{ "StudentFirstName" : "John" } { "StudentFirstName" : "Robert" } { "StudentFirstName" : "Chris" }