IDBKeyRange: lower property

The lower read-only property of the IDBKeyRange interface returns the lower bound of the key range.

Note: This feature is available in Web Workers

Value

The lower bound of the key range (can be any type.)

Examples

The following example illustrates how you'd use a key range. Here we declare keyRangeValue = IDBKeyRange.upperBound("F", "W", true, true); — a range that includes everything between "F" and "W" but not including them — since both the upper and lower bounds have been declared as open (true). We open a transaction (using IDBTransaction) and an object store, and open a Cursor with IDBObjectStore.openCursor, declaring keyRangeValue as its optional key range value.

After declaring the key range, we log its lower property value to the console, which should appear as "F".

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.

js

function displayData() {
  const keyRangeValue = IDBKeyRange.bound("F", "W", true, true);
  console.log(keyRangeValue.lower);

  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

Specification
Indexed Database API 3.0
# ref-for-dom-idbkeyrange-lower①

Browser compatibility

BCD tables only load in the browser

See also