files/en-us/web/api/idbindex/multientry/index.md
{{ APIRef("IndexedDB") }} {{AvailableInWorkers}}
The multiEntry read-only property of the
{{domxref("IDBIndex")}} interface returns a boolean value that affects how the index
behaves when the result of evaluating the index's key path yields an array.
This is decided when the index is created, using the
{{domxref("IDBObjectStore.createIndex")}} method. This method takes an optional
options parameter whose multiEntry property is set to true/false.
A boolean value:
| Value | Effect |
|---|---|
| true | There is one record in the index for each item in an array of keys. |
| false | There is one record for each key that is an array. |
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 {{domxref("IDBIndex.openCursor")}} — this works the same as opening a
cursor directly on an ObjectStore using
{{domxref("IDBObjectStore.openCursor")}} except that the returned records are sorted
based on the index, not the primary key.
The multi-entry status of the index is logged to the console: it should be returned
as 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).
function displayDataByIndex() {
tableEntry.textContent = "";
const transaction = db.transaction(["contactsList"], "readonly");
const objectStore = transaction.objectStore("contactsList");
const myIndex = objectStore.index("lName");
console.log(myIndex.multiEntry);
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}}
{{Compat}}