web api static method

IDBKeyRange: upperBound() static method

Available in workers

The upperBound() static method of the IDBKeyRange interface creates a new upper-bound key range. By default, it includes the upper endpoint value and is closed.

Syntax

IDBKeyRange.upperBound(upper)
IDBKeyRange.upperBound(upper, open)

Parameters

upper
- : Specifies the upper bound of the new key range.
open Optional
- : Indicates whether the upper bound excludes the endpoint value. The default is false.

Return value

IDBKeyRange: The newly created key range.

Exceptions

DataError DOMException
- : Thrown if the key associated with the upper parameter is not a valid key.

Examples

The following example illustrates how you’d use an upper bound key range. Here we declare keyRangeValue = IDBKeyRange.upperBound("F"); — a range that includes the value “F” and everything before it. We open a transaction (using IDBTransaction) and an object store, and open a Cursor with openCursor, declaring keyRangeValue as its optional key range value.

If we used IDBKeyRange.upperBound("F", true);, then the range excludes “F”; and instead only includes the values before it.

[!NOTE] For a more complete example allowing you to experiment with key range, have a look at our IDBKeyRange-example repo (view the example live too.)

function displayData() {
  const keyRangeValue = IDBKeyRange.upperBound("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.");
    }
  };
}

Specifications

SpecificationsStandards references are available on the canonical MDN page.

Browser compatibility

Browser compatibilityCompatibility data is available on the canonical MDN page.