IDBObjectStore.put() - Web API 接口参考 编辑

 IDBObjectStore 接口的  put() 方法更新一条给定的数据库记录,如果给出的值不存在,则插入一个新的记录

它返回一个 IDBRequest 对象,并且在一个单独的线程 ,创建一个值的 structured clone ,并且把它的值储存在对象仓库(object store)中. 当事务的模式是readwrite时,这个方法用来添加新的记录,或者更新一条对象仓库(object store)中已存在的记录 . 如果记录被成功储存, then a success event is fired on the returned request object with the result set to the key for the stored record, and the transaction set to the transaction in which this object store is opened.

put方法是一个插入或更新对象仓库的方法. 参考仅用于插入的方法 IDBObjectStore.add 方法.

谨记,如果你有一条 IDBCursor 记录想要更新, 使用IDBCursor.update() 方法更新,比 IDBObjectStore.put() 方法更合适. 这样做可以清楚地表明将更新现有记录，而不是插入新记录.

Note: 此特性在 Web Worker 中可用。

语法

var request = objectStore.put(item);
var request = objectStore.put(item, key);

参数

item

你想要更新 (或插入)的记录.

key 可选

你想要更新记录的主键 (e.g. from IDBCursor.primaryKey). This is only needed for object stores that have an autoIncrement primary key, therefore the key is not in a field on the record object. In such cases, calling put(item) will always insert a new record, because it doesn't know what existing record you might want to modify.

返回值

一个 IDBRequest 对象 ,在该对象上触发与此操作相关的后续事件。

异常

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

Exception	Description
ReadOnlyError	The transaction associated with this operation is in read-only mode.
TransactionInactiveError	This IDBObjectStore's transaction is inactive.
DataError	Any of the following conditions apply: The object store uses in-line keys or has a key generator, and a key parameter was provided. The object store uses out-of-line keys and has no key generator, and no key parameter was provided. The object store uses in-line keys but no key generator, and the object store's key path does not yield a valid key. The key parameter was provided but does not contain a valid key.
InvalidStateError	The IDBObjectStore has been deleted or removed.
DataCloneError	The data being stored could not be cloned by the internal structured cloning algorithm.

参数

value

被储存的值.

key

识别记录的键. 如果没有声明,那么记录键值将为空. 如果对象仓库有一个键生成器(e.g. autoincrement) ,必须传入key来更新对象.

Example

The following example requests a given record title; when that request is successful the onsuccess function gets the associated record from the IDBObjectStore (made available as objectStoreTitleRequest.result), updates one property of the record, and then puts the updated record back into the object store in another request with put(). For a full working example, see our To-do Notifications app (view example live.)

var title = "Walk dog";

// Open up a transaction as usual
var objectStore = db.transaction(['toDoList'], "readwrite").objectStore('toDoList');

// Get the to-do list object that has this title as it's title
var objectStoreTitleRequest = objectStore.get(title);

objectStoreTitleRequest.onsuccess = function() {
  // Grab the data object returned as the result
  var data = objectStoreTitleRequest.result;

  // Update the notified value in the object to "yes"
  data.notified = "yes";

  // Create another request that inserts the item back into the database
  var updateTitleRequest = objectStore.put(data);

  // Log the transaction that originated this request
  console.log("The transaction that originated this request is " + updateTitleRequest.transaction);

  // When this new request succeeds, run the displayData() function again to update the display
  updateTitleRequest.onsuccess = function() {
    displayData();
  };
};

Specification

Specification	Status	Comment
Indexed Database API 2.0 put()	Recommendation
Indexed Database API Draft put()	Recommendation

Browser compatibility

BCD tables only load in the browser

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.

See also

• Using IndexedDB
• Starting transactions: IDBDatabase
• Using transactions: IDBTransaction
• Setting a range of keys: IDBKeyRange
• Retrieving and making changes to your data: IDBObjectStore
• Using cursors: IDBCursor
• Reference example: To-do Notifications (view example live.)