IDBObjectStore.openCursor

To determine if the add operation has completed successfully, listen for the results’s success event.

语法

var request = ObjectStore.openCursor(optionalKeyRange, optionalDirection);

返回

An IDBRequest object on which subsequent events related to this operation are fired.

异常

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

例子

In this simple fragment we create a transaction, retrieve an object store, then use a cursor to iterate through all the records in the object store:

var transaction = db.transaction("name", "readonly");
var objectStore = transaction.objectStore("name");
var request = objectStore.openCursor();
request.onsuccess = function(event) {
  var cursor = event.target.result;
  if(cursor) {
    // cursor.value contains the current record being iterated through
    // this is where you'd do something with the result
    cursor.continue();
  } else {
    // no more results
  }
};

参数

range

The key range to be queried. If a single valid key is passed, this will default to a range containing only that key. If nothing is passed, this will default to a key range that selects all the records in this object store.

direction

An IDBCursorDirection telling the cursor what direction to travel. Defaults to "next".

Specification

浏览器兼容性

另请参阅

• 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.)