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 IDBObjectStore
and IDBIndex
objects 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 in the value range A–Z.
A key range can be 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:
Range | Code |
---|---|
All keys ≥ x |
IDBKeyRange.lowerBound (x)
|
All keys > x |
IDBKeyRange.lowerBound (x, true)
|
All keys ≤ y |
IDBKeyRange.upperBound (y)
|
All keys < y |
IDBKeyRange.upperBound (y, true)
|
All keys ≥ x && ≤ y |
IDBKeyRange.bound (x, y)
|
All keys > x &&< y |
IDBKeyRange.bound (x, y, true, true)
|
All keys > x && ≤ y |
IDBKeyRange.bound (x, y, true, false)
|
All keys ≥ x &&< y |
IDBKeyRange.bound (x, y, false, true)
|
The key = z |
IDBKeyRange.only (z)
|
A key is in a key range if the following conditions are true:
- The lower value of the key range is one of the following:
undefined
- Less than key value
- Equal to key value if
lowerOpen
isfalse
.
- The upper value of the key range is one of the following:
undefined
- Greater than key value
- Equal to key value if
upperOpen
isfalse
.
Note: This feature is available in Web Workers