insert - in collection dogs where have document with field age=1
var r = yield db.collection('dogs').insertOne({name:"fido", age:1});

assert.equal(1, r.insertedCount);

//single insert where have 2rd parameter to insertOne() that has call back function that check for errors

  db.collection('dogs').insertOne({ name: "fido", age: 1 }, function(err, res) {
    if (err) throw err;
    console.log("1 document inserted");
    db.close();
  });

//multiple inserts - in collection dogs where have 2 new documents inserted

var r = yield db.collection('dogs').insertMany([{name:"spot" , age:2}, {name:"rex", age:3}]);

assert.equal(2, r.insertedCount);

//Another multiple insert example-- where check if any errors and inserting on the collection called customers
   var myobj = [
    { name: 'John', address: 'Highway 71'},
     { name: 'Peter', address: 'Lowstreet 4'},
    { name: 'Amy',  address: 'Apple st 652'},
    { name: 'Hannah', address:  'Mountain 21'},
    { name: 'Michael', address: 'Valley 345'},
    { name: 'Sandy', address: 'Ocean blvd 2'},
     { name: 'Betty', address: 'Green Grass 1'},
    { name:  'Richard', address: 'Sky st 331'},
    { name: 'Susan',  address: 'One way 98'},
    { name: 'Vicky', address:  'Yellow Garden 2'},
    { name: 'Ben', address: 'Park Lane 38'},
    { name: 'William', address: 'Central st 954'},
     { name: 'Chuck', address: 'Main Road 989'},
    { name:  'Viola', address: 'Sideway 1633'}
  ];
  db.collection("customers").insertMany(myobj,  function(err, res) {
    if (err) throw err;
     console.log("Number of documents inserted: " + res.insertedCount);
     db.close();
  });
});

//Example that finds ALL the documents in the dogs collection & gets results in an array you can cycle through

db.collection("dogs").find({}).toArray(function(err, result) {
     if (err) throw err;
    console.log(result); //simply dump out the results but, result is an array result[i] is ith document retrieved.

       for(i=0; i< result.length; i++)
              console.log(result[i]);
     db.close();
  });

//Example that finds all the dogs with age 3

  var query = {age: 3}; //query is comma separated conditional --JSON format
  db.collection("dogs").find(query).toArray(function(err, result) {
    if (err) throw err;
    console.log(result);
    db.close();
  });

//FIND example--where cycle through the returned documents as a cursor type datastructure rather than array
// Get the collection
var col = db.collection('dogs');

// Save find results in local variable cursor

var cursor = col.find({age:1}).limit(2); //find the first 2 dog documents ("entries") that have the field of age=1

// Iterate over retrieved documents

while(yield cursor.hasNext()) {

     var doc = yield cursor.next();

     console.dir(doc);

}

// Example that finds all the dogs in a collection and then applies sort on them based on alphanumeric ordering on the name field

var mysort = { name: 1 }; //specifies alphanumeric sort on field name
  db.collection("dogs").find().sort(mysort).toArray(function(err, result) {
    if (err) throw err;
    console.log(result);
    db.close();
  });

VISIT the API page for more examples including REGULAR expresssions for finding certain string patterns

https://mongodb.github.io/node-mongodb-native/markdown-docs/queries.html

//UPDATING

//first setup the collection

var col = db.collection('dogs');
// Insert a single document
var r = yield col.insertMany([{name:"fido", age:1}, {name:"spot", age:2}, {name:"rex", age:3}]);
assert.equal(3, r.insertedCount);

// Update a single document

var r = yield col.updateOne({name:"fido"}, {$set: {age: 2}}); //change fido dog's age to 2
assert.equal(1, r.matchedCount);
assert.equal(1, r.modifiedCount);

// Update multiple documents
var r = yield col.updateMany({age:2}, {$set: {age: 3}}); //change all dogs with age of 2 to age 3
assert.equal(2, r.matchedCount);
assert.equal(2, r.modifiedCount);

//first setup the collection

var col = db.collection('dogs');

// Insert a some dogs first

var r = yield col.insertMany([{name:"fido", age:1}, {name:"spot", age:2}, {name:"rex", age:2}]);
assert.equal(3, r.insertedCount);

//delete the first docuemnt found with age= 1
var r = yield col.deleteOne({age:1});
assert.equal(1, r.deletedCount);

//delete multiple documents found with age=2
var r = yield col.deleteMany({age:2});
assert.equal(2, r.deletedCount);