The key
property of the IDBCursor
interface returns the key for the record at the cursor's position. If the cursor is outside its range, this is set to undefined. The cursor's key can be any data type.
cursor.key;
The value can be of any type.
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. Within each iteration we log the key of the cursor to the console, something like this (its the album title in each case, which is our key).
The cursor does not require us to select the data based on a key; we can just grab all of it. Also note that in each iteration of the loop, you can grab data from the current record under the cursor object using cursor.value.foo
. For a complete working example, see our IDBCursor example (view example live.)
function displayData() {
var transaction = db.transaction(['rushAlbumList'], "readonly");
var objectStore = transaction.objectStore('rushAlbumList');
objectStore.openCursor().onsuccess = function(event) {
var cursor = event.target.result;
if(cursor) {
var listItem = document.createElement('li');
listItem.innerHTML = cursor.value.albumTitle + ', ' + cursor.value.year;
list.appendChild(listItem);
console.log(cursor.key);
cursor.continue();
} else {
console.log('Entries all displayed.');
}
};
};
Specification | Status | Comment |
---|---|---|
Indexed Database API The definition of 'key' in that specification. | Recommendation |
Feature | Chrome | Edge | Firefox (Gecko) | Internet Explorer | Opera | Safari (WebKit) |
---|---|---|---|---|---|---|
Basic support | 23webkit 24 | (Yes) | 10 moz 16.0 (16.0) | 10, partial | 15 | 7.1 |
Available in workers | (Yes) | (Yes) | 37.0 (37.0) | ? | (Yes) | ? |
Binary keys | ? | ? | 51.0 (51.0) | ? | ? | ? |
Feature | Android | Android Webview | Edge | Firefox Mobile (Gecko) | IE Phone | Opera Mobile | Safari Mobile | Chrome for Android |
---|---|---|---|---|---|---|---|---|
Basic support | 4.4 | (Yes) | (Yes) | 22.0 (22.0) | 10 | 22 | 8 | (Yes) |
Available in workers | (Yes) | (Yes) | (Yes) | 37.0 (37.0) | ? | (Yes) | ? | (Yes) |
Binary keys | ? | ? | ? | 51.0 (51.0) | ? | ? | ? | ? |
IDBDatabase
IDBTransaction
IDBKeyRange
IDBObjectStore
IDBCursor
© 2005–2017 Mozilla Developer Network and individual contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/API/IDBCursor/key