var MongoClient = require('mongodb').MongoClient;
var url = "mongodb://localhost:27017/";

MongoClient.connect(url,{ useNewUrlParser: true }, function(err, db) {
  if (err) throw err;
  var dbo = db.db("latihandb");
  var myquery = { "email": /@gmail/ };
  dbo.collection("author").deleteMany(myquery, function(err, obj) {
    if (err) throw err;
    console.log(obj.result.n + " document(s) deleted");
    db.close();
  });
});