IDBIndex: objectStore property

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since September 2021.

Note: This feature is available in Web Workers.

The objectStore property of the IDBIndex interface returns the object store referenced by the current index.

Value

An IDBObjectStore.

Examples

In the following example we open a transaction and an object store, then get the index lName from a simple contacts database. We then open a basic cursor on the index using IDBIndex.openCursor. This works the same as opening a cursor directly on an ObjectStore using IDBObjectStore.openCursor except that the returned records are sorted based on the index, not the primary key.

The current object store is logged to the console: it should be returned something like this:

json
IDBObjectStore { name: "contactsList", keyPath: "id", indexNames: DOMStringList[7], transaction: IDBTransaction, autoIncrement: false }

Finally, we iterate through each record, and insert the data into an HTML table. For a complete working example, see our IndexedDB-examples demo repo (View the example live).

js
function displayDataByIndex() {
  tableEntry.textContent = "";
  const transaction = db.transaction(["contactsList"], "readonly");
  const objectStore = transaction.objectStore("contactsList");

  const myIndex = objectStore.index("lName");
  console.log(myIndex.objectStore);

  myIndex.openCursor().onsuccess = (event) => {
    const cursor = event.target.result;
    if (cursor) {
      const tableRow = document.createElement("tr");
      for (const cell of [
        cursor.value.id,
        cursor.value.lName,
        cursor.value.fName,
        cursor.value.jTitle,
        cursor.value.company,
        cursor.value.eMail,
        cursor.value.phone,
        cursor.value.age,
      ]) {
        const tableCell = document.createElement("td");
        tableCell.textContent = cell;
        tableRow.appendChild(tableCell);
      }
      tableEntry.appendChild(tableRow);

      cursor.continue();
    } else {
      console.log("Entries all displayed.");
    }
  };
}

Specifications

Specification
Indexed Database API 3.0
# ref-for-dom-idbindex-objectstore①

Browser compatibility

BCD tables only load in the browser

See also