how save of mongoose works code example

Example 1: mongoose save method

var Tank = mongoose.model('Tank', yourSchema);

var small = new Tank({ size: 'small' });
small.save(function (err) {
  if (err) return handleError(err);
  // saved!
});

// or

Tank.create({ size: 'small' }, function (err, small) {
  if (err) return handleError(err);
  // saved!
});

// or, for inserting large batches of documents
Tank.insertMany([{ size: 'small' }], function(err) {

});

Example 2: node mongoose save document

// Example for a model called Person with two properties, e.g. name, surname
// Values to be saved
const person = { name: Jane, surname: Doe};
// you can access the _id property from savedPerson variable (savedPerson._id)
savedPerson = await new Person(person).save()