IDBTransaction: error event

The error event is fired on IDBTransaction when a request returns an error and the event bubbles up to the transaction object.

Note: To handle all non-successful completion of the transaction, consider listening error instead.

Syntax

Use the event name in methods like addEventListener(), or set an event handler property.

addEventListener('error', event => { });
onerror = event => { };

Event type

A generic Event.

Bubbling

This event bubbles to IDBDatabase. The event.target property refers to the IDBTransaction object that bubbles up.

For more information, see Event bubbling and capture.

Examples

This example opens a database and tries to add a record, listening for the error event for the add() operation (this will occur if, for example, a record with the given taskTitle already exists):

// Open the database
const dBOpenRequest = window.indexedDB.open('toDoList', 4);

dBOpenRequest.onupgradeneeded = event => {
  const db = event.target.result;

  // Create an objectStore for this database
  const objectStore = db.createObjectStore('toDoList', { keyPath: 'taskTitle' });

  // define what data items the objectStore will contain
  objectStore.createIndex('hours', 'hours', { unique: false });
  objectStore.createIndex('minutes', 'minutes', { unique: false });
  objectStore.createIndex('day', 'day', { unique: false });
  objectStore.createIndex('month', 'month', { unique: false });
  objectStore.createIndex('year', 'year', { unique: false });
};

dBOpenRequest.onsuccess = event => {
  const db = dBOpenRequest.result;

  // open a read/write db transaction, ready for adding the data
  const transaction = db.transaction(['toDoList'], 'readwrite');

  transaction.addEventListener('error', () => {
    console.log(`Error adding new item: ${newItem.taskTitle}`);
  });

  const objectStore = transaction.objectStore('toDoList');
  const newItem = { taskTitle: 'my task', hours: 10, minutes: 10, day: 10, month: 'January', year: 2020 };

  const objectStoreRequest = objectStore.add(newItem);
};

The same example, using the onerror property instead of addEventListener():

// Open the database
const dBOpenRequest = window.indexedDB.open('toDoList', 4);

dBOpenRequest.onupgradeneeded = event => {
  const db = event.target.result;

  // Create an objectStore for this database
  const objectStore = db.createObjectStore('toDoList', { keyPath: 'taskTitle' });

  // define what data items the objectStore will contain
  objectStore.createIndex('hours', 'hours', { unique: false });
  objectStore.createIndex('minutes', 'minutes', { unique: false });
  objectStore.createIndex('day', 'day', { unique: false });
  objectStore.createIndex('month', 'month', { unique: false });
  objectStore.createIndex('year', 'year', { unique: false });
};

dBOpenRequest.onsuccess = event => {
  const db = dBOpenRequest.result;

  // open a read/write db transaction, ready for adding the data
  const transaction = db.transaction(['toDoList'], 'readwrite');

  transaction.onerror = () => {
    console.log(`Error adding new item: ${newItem.taskTitle}`);
  };

  const objectStore = transaction.objectStore('toDoList');
  const newItem = { taskTitle: 'my task', hours: 10, minutes: 10, day: 10, month: 'January', year: 2020 };

  const objectStoreRequest = objectStore.add(newItem);
};

Browser compatibility

BCD tables only load in the browser

See also