在此页

• 特性
• 方法
• 范例
• 规范
• 浏览器兼容性
• 另请参阅
• 相关话题

IDBIndex 接口在 IndexedDB API provides asynchronous access to an index in a database. An index is a kind of object store for looking up records in another object store, called the referenced object store. You use this interface to retrieve data.

You can retrieve records in an object store through the primary key or by using an index. An index lets you look up records in an object store using properties of the values in the object stores records other than the primary key

The index is a persistent key-value storage where the value part of its records is the key part of a record in the referenced object store. The records in an index are automatically populated whenever records in the referenced object store are inserted, updated, or deleted. Each record in an index can point to only one record in its referenced object store, but several indexes can reference the same object store. When the object store changes, all indexes that refers to the object store are automatically updated.

You can grab a set of keys within a range. To learn more, see IDBKeyRange .

注意： 此特征可用于 Web 工作者 .

特性

IDBIndex.isAutoLocale 只读

返回 布尔 indicating whether the index had a locale value of auto specified upon its creation (see createIndex() 's optionalParameters )。

IDBIndex.locale 只读

Returns the locale of the index (for example en-US ，或 pl ) if it had a locale value specified upon its creation (see createIndex() 's optionalParameters )。

IDBIndex.name

The name of this index.

IDBIndex.objectStore 只读

The name of the object store referenced by this index.

IDBIndex.keyPath 只读

key path of this index. If null, this index is not auto-populated .

IDBIndex.multiEntry 只读

Affects how the index behaves when the result of evaluating the index's key path yields an array. If true , there is one record in the index for each item in an array of keys. If false , then there is one record for each key that is an array.

IDBIndex.unique 只读

若 true , this index does not allow duplicate values for a key.

方法

继承自： EventTarget

IDBIndex.count()

返回 IDBRequest object, and in a separate thread, returns the number of records within a key range.

IDBIndex.get()

返回 IDBRequest object, and, in a separate thread, finds either the value in the referenced object store that corresponds to the given key or the first corresponding value, if key 是 IDBKeyRange .

IDBIndex.getKey()

返回 IDBRequest object, and, in a separate thread, finds either the given key or the primary key, if key 是 IDBKeyRange .

IDBIndex.getAll()

返回 IDBRequest object, in a separate thread, finds all matching values in the referenced object store that correspond to the given key or are in range, if key 是 IDBKeyRange .

IDBIndex.getAllKeys()

返回 IDBRequest object, in a separate thread, finds all matching keys in the referenced object store that correspond to the given key or are in range, if key 是 IDBKeyRange .

IDBIndex.openCursor()

返回 IDBRequest object, and, in a separate thread, creates a cursor over the specified key range.

IDBIndex.openKeyCursor()

返回 IDBRequest object, and, in a separate thread, creates a cursor over the specified key range, as arranged by this index.

范例

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 使用 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.');
    }
  };
};
					

规范

规范	状态	注释
索引数据库 API 2.0 The definition of 'IDBIndex' in that specification.	推荐
索引数据库 API 草案 The definition of 'IDBIndex' in that specification.	推荐

浏览器兼容性

The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request. 更新 GitHub 上的兼容性数据

	桌面						移动
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
IDBIndex	Chrome 24 24 不支持 23 — 57 Prefixed Prefixed Implemented with the vendor prefix: webkit	Edge 12	Firefox 16 16 不支持 10 — 16 Prefixed Prefixed Implemented with the vendor prefix: moz	IE 部分支持 10	Opera 15	Safari 7	WebView Android Yes Yes 不支持 ? — 57 Prefixed Prefixed Implemented with the vendor prefix: webkit	Chrome Android 25 25 不支持 25 — 57 Prefixed Prefixed Implemented with the vendor prefix: webkit	Firefox Android 22	Opera Android 14	Safari iOS 8	Samsung Internet Android 1.5 1.5 不支持 1.5 — 7.0 Prefixed Prefixed Implemented with the vendor prefix: webkit
count	Chrome 24 24 不支持 23 — 24 Prefixed Prefixed Implemented with the vendor prefix: webkit	Edge 12	Firefox 16 16 不支持 10 — 16 Prefixed Prefixed Implemented with the vendor prefix: moz	IE 部分支持 10	Opera 15	Safari 7	WebView Android Yes Yes 不支持 ? — ? Prefixed Prefixed Implemented with the vendor prefix: webkit	Chrome Android 25	Firefox Android 22	Opera Android 14	Safari iOS 8	Samsung Internet Android 1.5
get	Chrome 24 24 不支持 23 — 24 Prefixed Prefixed Implemented with the vendor prefix: webkit	Edge 12	Firefox 16 16 不支持 10 — 16 Prefixed Prefixed Implemented with the vendor prefix: moz	IE 部分支持 10	Opera 15	Safari 7	WebView Android Yes Yes 不支持 ? — ? Prefixed Prefixed Implemented with the vendor prefix: webkit	Chrome Android 25	Firefox Android 22	Opera Android 14	Safari iOS 8	Samsung Internet Android 1.5
getAll	Chrome 48	Edge ≤18	Firefox 44	IE No	Opera 35	Safari 10.1	WebView Android 48	Chrome Android 48	Firefox Android 44	Opera Android 35	Safari iOS 10.3	Samsung Internet Android 5.0
getAllKeys	Chrome 48	Edge ≤18	Firefox 44 Disabled 44 Disabled Disabled From version 44: this feature is behind the dom.indexedDB.experimental preference. To change preferences in Firefox, visit about:config.	IE No	Opera 35	Safari 10.1	WebView Android 48	Chrome Android 48	Firefox Android 44 Disabled 44 Disabled Disabled From version 44: this feature is behind the dom.indexedDB.experimental preference. To change preferences in Firefox, visit about:config.	Opera Android 35	Safari iOS 10.3	Samsung Internet Android 5.0
getKey	Chrome 24 24 不支持 23 — 24 Prefixed Prefixed Implemented with the vendor prefix: webkit	Edge 12	Firefox 16 16 不支持 10 — 16 Prefixed Prefixed Implemented with the vendor prefix: moz	IE 部分支持 10	Opera 15	Safari 7	WebView Android Yes Yes 不支持 ? — ? Prefixed Prefixed Implemented with the vendor prefix: webkit	Chrome Android 25	Firefox Android 22	Opera Android 14	Safari iOS 8	Samsung Internet Android 1.5
isAutoLocale 非标	Chrome No	Edge No	Firefox 43	IE No	Opera No	Safari No	WebView Android No	Chrome Android No	Firefox Android 43	Opera Android No	Safari iOS No	Samsung Internet Android No
keyPath	Chrome 24 24 不支持 23 — 24 Prefixed Prefixed Implemented with the vendor prefix: webkit	Edge 12	Firefox 16 16 不支持 10 — 16 Prefixed Prefixed Implemented with the vendor prefix: moz	IE 部分支持 10	Opera 15	Safari 7	WebView Android Yes Yes 不支持 ? — ? Prefixed Prefixed Implemented with the vendor prefix: webkit	Chrome Android 25	Firefox Android 22	Opera Android 14	Safari iOS 8	Samsung Internet Android 1.5
locale 非标	Chrome No	Edge No	Firefox 43	IE No	Opera No	Safari No	WebView Android No	Chrome Android No	Firefox Android 43	Opera Android No	Safari iOS No	Samsung Internet Android No
multiEntry	Chrome 24 24 不支持 23 — 24 Prefixed Prefixed Implemented with the vendor prefix: webkit	Edge 12	Firefox 16 16 不支持 10 — 16 Prefixed Prefixed Implemented with the vendor prefix: moz	IE 部分支持 10	Opera 15	Safari 7	WebView Android Yes Yes 不支持 ? — ? Prefixed Prefixed Implemented with the vendor prefix: webkit	Chrome Android 25	Firefox Android 22	Opera Android 14	Safari iOS 8	Samsung Internet Android 1.5
名称	Chrome 24 24 不支持 23 — 24 Prefixed Prefixed Implemented with the vendor prefix: webkit	Edge 12	Firefox 16 16 不支持 10 — 16 Prefixed Prefixed Implemented with the vendor prefix: moz	IE 部分支持 10	Opera 15	Safari 7	WebView Android Yes Yes 不支持 ? — ? Prefixed Prefixed Implemented with the vendor prefix: webkit	Chrome Android 25	Firefox Android 22	Opera Android 14	Safari iOS 8	Samsung Internet Android 1.5
objectStore	Chrome 24 24 不支持 23 — 24 Prefixed Prefixed Implemented with the vendor prefix: webkit	Edge 12	Firefox 16 16 不支持 10 — 16 Prefixed Prefixed Implemented with the vendor prefix: moz	IE 部分支持 10	Opera 15	Safari 7	WebView Android Yes Yes 不支持 ? — ? Prefixed Prefixed Implemented with the vendor prefix: webkit	Chrome Android 25	Firefox Android 22	Opera Android 14	Safari iOS 8	Samsung Internet Android 1.5
openCursor	Chrome 24 24 不支持 23 — 24 Prefixed Prefixed Implemented with the vendor prefix: webkit	Edge 12	Firefox 16 16 不支持 10 — 16 Prefixed Prefixed Implemented with the vendor prefix: moz	IE 部分支持 10	Opera 15	Safari 7	WebView Android Yes Yes 不支持 ? — ? Prefixed Prefixed Implemented with the vendor prefix: webkit	Chrome Android 25	Firefox Android 22	Opera Android 14	Safari iOS 8	Samsung Internet Android 1.5
openKeyCursor	Chrome 24 24 不支持 23 — 24 Prefixed Prefixed Implemented with the vendor prefix: webkit	Edge 12	Firefox 16 16 不支持 10 — 16 Prefixed Prefixed Implemented with the vendor prefix: moz	IE 部分支持 10	Opera 15	Safari 7	WebView Android Yes Yes 不支持 ? — ? Prefixed Prefixed Implemented with the vendor prefix: webkit	Chrome Android 25	Firefox Android 22	Opera Android 14	Safari iOS 8	Samsung Internet Android 1.5
unique	Chrome 24 24 不支持 23 — 24 Prefixed Prefixed Implemented with the vendor prefix: webkit	Edge 12	Firefox 16 16 不支持 10 — 16 Prefixed Prefixed Implemented with the vendor prefix: moz	IE 部分支持 10	Opera 15	Safari 7	WebView Android Yes Yes 不支持 ? — ? Prefixed Prefixed Implemented with the vendor prefix: webkit	Chrome Android 25	Firefox Android 22	Opera Android 14	Safari iOS 8	Samsung Internet Android 1.5
Available in workers	Chrome Yes	Edge ≤18	Firefox 37	IE ?	Opera Yes	Safari ?	WebView Android Yes	Chrome Android Yes	Firefox Android 37	Opera Android Yes	Safari iOS ?	Samsung Internet Android Yes

图例

完整支持

完整支持

部分支持

部分支持

不支持

不支持

兼容性未知 ?

兼容性未知

实验。期望将来行为有所改变。

实验。期望将来行为有所改变。

非标。预期跨浏览器支持较差。

非标。预期跨浏览器支持较差。

用户必须明确启用此特征。

用户必须明确启用此特征。

要求使用供应商前缀或不同名称。

要求使用供应商前缀或不同名称。

另请参阅

• 使用 IndexedDB
• 开始事务： IDBDatabase
• 使用事务： IDBTransaction
• 设置一系列键： IDBKeyRange
• 检索并使您的数据改变： IDBObjectStore
• 使用光标： IDBCursor
• 参考范例： 待办通知 ( 实时查看范例 )。

元数据

• 最后修改： 2020 年 1 月 22 日

相关话题

1. IndexedDB API
2. IDBIndex
3. 特性

   1. isAutoLocale
   2. keyPath
   3. locale
   4. multiEntry
   5. 名称
   6. objectStore
   7. unique
4. 方法

   1. count()
   2. get()
   3. getAll()
   4. getAllKeys()
   5. getKey()
   6. openCursor()
   7. openKeyCursor()
5. IndexedDB 相关页面

   1. IDBCursor
   2. IDBCursorSync
   3. IDBCursorWithValue
   4. IDBDatabase
   5. IDBDatabaseException
   6. IDBDatabaseSync
   7. IDBEnvironment
   8. IDBEnvironmentSync
   9. IDBFactory
   10. IDBFactorySync
   11. IDBIndexSync
   12. IDBKeyRange
   13. IDBObjectStore
   14. IDBObjectStoreSync
   15. IDBOpenDBRequest
   16. IDBRequest
   17. IDBTransaction
   18. IDBTransactionSync
   19. IDBVersionChangeEvent
   20. IDBVersionChangeRequest