IDBCursor.continuePrimaryKey()

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 cursor’s 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.

Note: This feature is available in Web Workers.

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:

  • The key is not a valid key.
  • The key is less than or equal to this cursor's position and the cursor's direction is next or nextunique.
  • The key is greater than or equal to this cursor's position and this cursor's direction is prev or prevunique.
InvalidStateError The cursor is currently being iterated or has iterated past its end.
InvalidAccessError The cursor's direction is not prev or next.

Example

here’s 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

Update compatibility data on GitHub
DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
continuePrimaryKeyChrome Full support 58Edge Full support 79Firefox Full support 51
Full support 51
No support 10 — 51
Prefixed
Prefixed Implemented with the vendor prefix: moz
IE ? Opera Full support 45Safari Full support 10.1WebView Android Full support 58Chrome Android Full support 58Firefox Android Full support 51Opera Android Full support 43Safari iOS Full support 10.3Samsung 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