Please note, this is a STATIC archive of website developer.mozilla.org from 03 Nov 2016, cach3.com does not collect or store any user information, there is no "phishing" involved.

IDBObjectStore.index()

我们的志愿者还没有将这篇文章翻译为 中文 (简体)加入我们帮助完成翻译!

The index() method of the IDBObjectStore interface opens a named index in the current object store, after which it can be used to, for example, return a series of records sorted by that index using a cursor. 

Note: This feature is available in Web Workers.

Syntax

objectStore.index(indexName);

Returns

An IDBIndex object for accessing the index.

Exceptions

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

Exception Description
InvalidStateError The source object store has been deleted, or the transaction for the object store has finished.
NotFoundError There is no index with the given name (case-sensitive) in the database.
 

Example

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 IDBIndex.openCursor — this works the same as opening a cursor directly on an ObjectStore using IDBObjectStore.openCursor except that the returned records are sorted based on the index, not the primary key.

Finally, we iterate through each record, and insert the data into an HTML table. For a complete working example, see our IDBIndex-example demo repo (View the example live.)

function displayDataByIndex() {
  tableEntry.innerHTML = '';
  var transaction = db.transaction(['contactsList'], 'readonly');
  var objectStore = transaction.objectStore('contactsList');

  var myIndex = objectStore.index('lName'); 
  myIndex.openCursor().onsuccess = function(event) {
    var cursor = event.target.result;
    if(cursor) {
      var tableRow = document.createElement('tr');
      tableRow.innerHTML =   '<td>' + cursor.value.id + '</td>'
                           + '<td>' + cursor.value.lName + '</td>'
                           + '<td>' + cursor.value.fName + '</td>'
                           + '<td>' + cursor.value.jTitle + '</td>'
                           + '<td>' + cursor.value.company + '</td>'
                           + '<td>' + cursor.value.eMail + '</td>'
                           + '<td>' + cursor.value.phone + '</td>'
                           + '<td>' + cursor.value.age + '</td>';
      tableEntry.appendChild(tableRow);  

      cursor.continue();
    } else {
      console.log('Entries all displayed.');    
    }
  };
};

Parameters

name
The name of the index to open.

Specification

Specification Status Comment
Indexed Database API
The definition of 'index()' in that specification.
Editor's Draft  

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
Available in workers (Yes) 37.0 (37.0) ? (Yes) ?
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 8
Available in workers (Yes) 37.0 (37.0) (Yes) ? (Yes) ?

See also

文档标签和贡献者

 此页面的贡献者: jpmedley, inexorabletash, chrisdavidmills, fscholz
 最后编辑者: jpmedley,