IDBObjectStore.deleteIndex()

The deleteIndex() method of the IDBObjectStore interface destroys the index with the specified name in the connected database, used during a version upgrade.

Note that this method must be called only from a VersionChange transaction mode callback. Note that this method synchronously modifies the IDBObjectStore.indexNames property.

Note: This feature is available in Web Workers

Syntax

objectStore.deleteIndex(indexName);

Parameters

indexName: The name of the existing index to remove.

Exceptions

This method may raise a DOMException of one of the following types:

Exception	Description
`InvalidStateError`	Occurs if the method was not called from a `versionchange` transaction mode callback.
`TransactionInactiveError`	Occurs if the transaction this `IDBObjectStore` belongs to is not active (e.g. has been deleted or removed.) In Firefox previous to version 41, an `InvalidStateError` was raised in this case as well, which was misleading; this has now been fixed (see bug 1176165.)
`NotFoundError`	Occurs if there is no index with the given name (case-sensitive) in the database.

In the following example you can see the IDBOpenDBRequest.onupgradeneeded handler being used to update the database structure if a database with a higher version number is loaded. IDBObjectStore.createIndex is used to create new indexes on the object store, after which we delete the unneeded old indexes with deleteIndex(). For a full working example, see our To-do Notifications app (view example live.)

var db;

// Let us open our database
var DBOpenRequest = window.indexedDB.open("toDoList", 4);

// these two event handlers act on the database being opened successfully, or not
DBOpenRequest.onerror = function(event) {
  note.innerHTML += '<li>Error loading database.</li>';
};

DBOpenRequest.onsuccess = function(event) {
  note.innerHTML += '<li>Database initialised.</li>';

  // store the result of opening the database in the db variable. This is used a lot below
  db = this.result;

  // Run the displayData() function to populate the task list with all the to-do list data already in the IDB
  displayData();
};

// This event handles the event whereby a new version of the database needs to be created
// Either one has not been created before, or a new version number has been submitted via the
// window.indexedDB.open line above
//it is only implemented in recent browsers
DBOpenRequest.onupgradeneeded = function(event) {
  var db = this.result;

  db.onerror = function(event) {
    note.innerHTML += '<li>Error loading database.</li>';
  };

  // Create an objectStore for this database
  var 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 });
  objectStore.createIndex("notified", "notified", { unique: false });

  objectStore.deleteIndex("seconds");
  objectStore.deleteIndex("contact");

};

Specifications

Specification
Indexed Database API 3.0 (Indexed DB 3.0) # ref-for-dom-idbobjectstore-deleteindex①

Browser compatibility

BCD tables only load in the browser