The continuePrimaryKey()
method of the IDBCursor
interface advances the cursor to the to the item whose key matches the key parameter as well as whose primary key matches the primary key parameter.
A typical use case, is to resume the iteration where a previous cursor has been closed, without having to compare the keys one by one.
Calling this method more than once before new cursor data has been loaded - for example, calling continuePrimaryKey()
twice from the same onsuccess handler - results in an InvalidStateError
being thrown on the second call because the cursorโs got value flag has been unset.
This method is only valid for cursors coming from an index. Using it for cursors coming from an object store will throw an error.
Syntax
cursor.continuePrimaryKey(key, primaryKey);
Parameters
key
- The key to position the cursor at.
primaryKey
- The primary key to position the cursor at.
Exceptions
This method may raise a DOMException
of one of the following types:
Exception | Description |
---|---|
TransactionInactiveError |
This IDBCursor's transaction is inactive. |
DataError |
The key parameter may have any of the following conditions:
|
InvalidStateError |
The cursor is currently being iterated or has iterated past its end. |
InvalidAccessError |
The cursor's direction is not prev or next . |
Example
hereโs how you can resume an iteration of all articles tagged with "javascript"
since your last visit:
let request = articleStore.index("tag").openCursor(); let count = 0; let unreadList = []; request.onsuccess = (event) => { let cursor = event.target.result; if (!cursor) { return; } let lastPrimaryKey = getLastIteratedArticleId(); if (lastPrimaryKey > cursor.primaryKey) { cursor.continuePrimaryKey("javascript", lastPrimaryKey); return; } // update lastIteratedArticleId setLastIteratedArticleId(cursor.primaryKey); // preload 5 articles into the unread list; unreadList.push(cursor.value); if (++count < 5) { cursor.continue(); } };
Specifications
Specification | Status | Comment |
---|---|---|
Indexed Database API Draft The definition of 'continuePrimaryKey()' in that specification. |
Recommendation |
Browser compatibility
Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
continuePrimaryKey | Chrome Full support 58 | Edge Full support 79 | Firefox
Full support
51
| IE ? | Opera Full support 45 | Safari Full support 10.1 | WebView Android Full support 58 | Chrome Android Full support 58 | Firefox Android Full support 51 | Opera Android Full support 43 | Safari iOS Full support 10.3 | Samsung Internet Android Full support 7.0 |
Legend
- Full support
- Full support
- Compatibility unknown
- Compatibility unknown
- Requires a vendor prefix or different name for use.
- Requires a vendor prefix or different name for use.
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.)