IDBFactory: databases() method

Baseline 2024

Newly available

Since May 2024, this feature works across the latest devices and browser versions. This feature might not work in older devices or browsers.

Note: This feature is available in Web Workers.

The databases method of the IDBFactory interface returns a Promise that fulfills with an array of objects containing the name and version of all the available databases.

This is a snapshot of the databases, intended primarily to allow web applications to check what databases have been created — in order to, for example, clean up databases created by earlier versions of application code.

Syntax

databases()

Parameters

None.

Return value

A Promise that fulfills with an array of objects representing a snapshot of the available databases (or rejects with the error/exceptions below).

Each array object has the following properties:

name

A database name.

version

The database version.

Note that the sequence on the returned objects is undefined.

Exceptions

SecurityError DOMException

Thrown if the method is called from an opaque origin or the user has disabled storage.

UnknownError DOMException

Thrown if the set of available databases cannot be determined for any reason.

Examples

Create and list databases

This example creates/opens a number of databases. On successful initialization of each database it lists all the available databases.

const logElement = document.querySelector("#log");
function log(text) {
  logElement.innerText = `${logElement.innerText}${text}\n`;
  logElement.scrollTop = logElement.scrollHeight;
}

#log {
  height: 240px;
  overflow: scroll;
  padding: 0.5rem;
  border: 1px solid black;
}

JavaScript

First we define the function that is used to get and log the available databases. This awaits on the promise returned by indexedDB.databases() and then iterates the array and lists the values of each element:

js
async function getDb() {
  const databases = await indexedDB.databases();
  log("List databases:");
  databases.forEach((element) => {
    log(`name: ${element.name}, version: ${element.version}`);
  });
}

To demonstrate how the above function is used, below we create two databases. For each database, we log just before the database is opened. We also log on successful initialization (or error) and then also log the available databases.

js
// Create a database named toDoList with default version (1)
const dbName1 = "toDoList";
log(`Opening: ${dbName1}`);
let DBOpenRequest = window.indexedDB.open(dbName1);

DBOpenRequest.addEventListener("error", (event) => {
  log(`Error opening: ${dbName1}`);
  getDb();
});

DBOpenRequest.addEventListener("success", (event) => {
  log(`Initialized: ${dbName1}`);
  getDb();
});

// Create database "AnotherDb"
const dbName2 = "AnotherDb";
log(`Opening ${dbName2}`);
DBOpenRequest = window.indexedDB.open(dbName2, 2);

DBOpenRequest.addEventListener("error", (event) => {
  log(`Error opening: ${dbName2}`);
  getDb();
});

DBOpenRequest.addEventListener("success", (event) => {
  log(`Initialized: ${dbName2}`);
  getDb();
});