The IDBKeyRange interface of the IndexedDB API represents a continuous interval
over some data type that is used for keys. Records can be retrieved from object
stores and indexes using keys or a range of keys. You can limit the range using
lower and upper bounds. For example, you can iterate over all values of a key
between x and y.
A key range can have a single value or a range with upper and lower bounds or
endpoints. If the key range has both upper and lower bounds, then it is bounded; if it
has no bounds, it is unbounded. A bounded key range can either be open (the endpoints
are excluded) or closed (the endpoints are included). To retrieve all keys within a
certain range, you can use the following code constructs:
The lower bound of the key range (can be any type.)
Returns false if the lower-bound value is included in the key range.
The upper bound of the key range (can be any type.)
Returns false if the upper-bound value is included in the key range.