Query BinData by Type in MongoDB

To query by type, use subtype() in MongoDB. Let us create a collection with documents −

> db.demo249.insertOne({ "_id" : BinData(0,"AQAAAAEBAAVlbl9VSwAAAAAAAAhv") }); {    "acknowledged" : true,    "insertedId" : BinData(0,"AQAAAAEBAAVlbl9VSwAAAAAAAAhv") } > db.demo249.insertOne({"_id" : BinData(4,"CNDF66qIlCY92q1vFAAAAQ==")}); {    "acknowledged" : true,    "insertedId" : UUID("08d0c5eb-aa88-9426-3dda-ad6f14000001") } > db.demo249.insertOne({"_id" : BinData(3,"CNDF66qJ29g92q1vFAAAEw==")}); {    "acknowledged" : true,    "insertedId" : BinData(3,"CNDF66qJ29g92q1vFAAAEw==") }

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

> db.demo249.find();

This will produce the following output −

{ "_id" : BinData(0,"AQAAAAEBAAVlbl9VSwAAAAAAAAhv") } { "_id" : UUID("08d0c5eb-aa88-9426-3dda-ad6f14000001") } { "_id" : BinData(3,"CNDF66qJ29g92q1vFAAAEw==") }

Following is how to query BinData by Type −

> db.demo249.find(function(){ return this._id.subtype() == 0 });

This will produce the following output −

{ "_id" : BinData(0,"AQAAAAEBAAVlbl9VSwAAAAAAAAhv")