how to use mongoose schema code example
Example 1: mongoose model
const schema = new mongoose.Schema({ name: 'string', size: 'string' });
const Tank = mongoose.model('Tank', schema);
Example 2: node js + mongoose
const db = mongoose.connection;
db.on('error', console.error.bind(console, 'connection error:'));
db.once('open', function() {
// we're connected!
});