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    IDBObjectStore.deleteIndex()

    This article is in need of a technical review.

    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.

    Syntax

    objectStore.deleteIndex(indexName);

    Returns

    Void.

    Exceptions

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

    Exception Description
    InvalidStateError The method was not called from a versionchange transaction mode callback.
    NotFoundError There is no index with the given name (case-sensitive) in the database.
     

    Example

    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 = request.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 = event.target.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");
    
    };

    Parameters

    indexName
    The name of the existing index to remove.
    Specifications
    Specification Status Comment
    Indexed Database API
    The definition of 'deleteIndex()' in that specification.
    Candidate Recommendation  

    Browser compatibility

    Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
    Basic support 23webkit
    24
    10 moz
    16.0 (16.0)
    10, partial 15 7.1
    Feature Android Firefox Mobile (Gecko) Firefox OS IE Phone Opera Mobile Safari Mobile
    Basic support 4.4 22.0 (22.0) 1.0.1 10 22 Not supported

    See also

    Document Tags and Contributors

    Contributors to this page: fscholz, chrisdavidmills
    Last updated by: fscholz,