IDBObjectStore.put()
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。
备注: 此特性在 Web Worker 中可用。
语法
put(item)
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 anautoIncrement
primary key, therefore the key is not in a field on the record object. In such cases, callingput(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:
|
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
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 |
---|
Indexed Database API 3.0 # ref-for-dom-idbobjectstore-put① |
Browser compatibility
BCD tables only load in the browser
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.)