I have an app that allows users to generate objects, and store them (in a MySQL table, as strings) for later use. The object could be :
function Obj() {
From ECMAScript 6 onwards you can just do:
Object.assign(new Obj(), JSON.parse(rawJsonString))
Note: You create a new empty object of the defined type first and then override its properties with the parsed JSON. Not the other way around.
The methods define behaviour and contain no variable data. They are "stored" as your code. So you don't actually have to store them in the database.