getAllKeys() method of the
IDBObjectStore interface returns an
IDBRequest object retrieves record keys for all objects in the object store matching the specified parameter or all objects in the store if no parameters are given.
If a value is successfully found, then a structured clone of it is created and set as the result of the request object.
This method produces the same result for:
- a record that doesn't exist in the database
- a record that has an undefined value
To tell these situations apart, you need to call the
openCursor() method with the same key. That method provides a cursor if the record exists, and no cursor if it does not.