As you can see in case 1, createObjectStore() accepts a second parameter that defines the key path of the object store. This is useful when you store objects: put() calls don’t need a second parameter—you can pass just the value (an object), and the key will be taken from the object property with that name.

The key path lets you retrieve a value by that property later, and it must be unique (every item must have a different value for that property).

The key can be set to auto-increment so you don’t need to track it in your client code:

db.createObjectStore('notes', { autoIncrement: true })

Use auto increment if your values do not contain a unique key already (for example, if you collect email addresses without an associated name).

Lessons in this unit:

0:	Introduction
1:	Loading the idb library
2:	Creating a database and a store
3:	Adding data into a store
4:	Retrieving data from a store
5:	Deleting data
6:	Migrations
7:	▶︎ Unique keys