IDBKeyRange

BaselineWidely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.

Note: This feature is available inWeb Workers.

TheIDBKeyRange interface of theIndexedDB API represents a continuous interval over some data type that is used for keys. Records can be retrieved fromIDBObjectStore andIDBIndex 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 isbounded; if it has no bounds, it isunbounded. 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 iflowerOpen isfalse.
The upper value of the key range is one of the following:
- undefined
- Greater than key value
- Equal to key value ifupperOpen isfalse.

Instance properties

IDBKeyRange.lowerRead only: Lower bound of the key range.
IDBKeyRange.upperRead only: Upper bound of the key range.
IDBKeyRange.lowerOpenRead only: Returns false if the lower-bound value is included in the key range.
IDBKeyRange.upperOpenRead only: Returns false if the upper-bound value is included in the key range.

Static methods

IDBKeyRange.bound(): Creates a new key range with upper and lower bounds.
IDBKeyRange.only(): Creates a new key range containing a single value.
IDBKeyRange.lowerBound(): Creates a new key range with only a lower bound.
IDBKeyRange.upperBound(): Creates a new upper-bound key range.

Instance methods

IDBKeyRange.includes(): Returns a boolean indicating whether a specified key is inside the key range.

Examples

The following example illustrates how you'd use a key range. Here we declare akeyRangeValue as a range between values of"A" and"F". We open a transaction (usingIDBTransaction) and an object store, and open a cursor withIDBObjectStore.openCursor, declaringkeyRangeValue as its optional key range value. This means that the cursor will only retrieve records with keys inside that range. This range includes the values"A" and"F", as we haven't declared that they should be open bounds.If we usedIDBKeyRange.bound("A", "F", true, true);, then the range would not include"A" and"F", only the values between them.

Note:For a more complete example allowing you to experiment with key range, have a look at ourIDBKeyRange-example repo (view the example live too.)

function displayData() {  const keyRangeValue = IDBKeyRange.bound("A", "F");  const transaction = db.transaction(["fThings"], "readonly");  const objectStore = transaction.objectStore("fThings");  objectStore.openCursor(keyRangeValue).onsuccess = (event) => {    const cursor = event.target.result;    if (cursor) {      const listItem = document.createElement("li");      listItem.textContent = `${cursor.value.fThing}, ${cursor.value.fRating}`;      list.appendChild(listItem);      cursor.continue();    } else {      console.log("Entries all displayed.");    }  };}