Schema Statics are methods that can be invoked directly by a Model (unlike Schema Methods, which need to be invoked by an instance of a Mongoose document). You assign a Static to a schema by adding the function to the schema's statics
object.
One example use case is for constructing custom queries:
userSchema.statics.findByName = function(name, callback) {
return this.model.find({ name: name }, callback);
}
var User = mongoose.model('User', userSchema)
User.findByName('Kobe', function(err, documents) {
console.log(documents)
})