IDBCursor.advance() - Web APIs 编辑

The advance() method of the IDBCursor interface sets the number of times a cursor should move its position forward.

Note:

This feature is available in Web Workers.

Syntax

cursor.advance(count);

Parameters

count
The number of times to move the cursor forward.

Exceptions

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

ExceptionDescription
TransactionInactiveErrorThis IDBCursor's transaction is inactive.
TypeErrorThe value passed into the count parameter was zero or a negative number.
InvalidStateErrorThe cursor is currently being iterated or has iterated past its end.
 

Example

In this simple fragment we create a transaction, retrieve an object store, then use a cursor to iterate through the records in the object store. Here we use cursor.advance(2) to jump 2 places forward each time, meaning that only every other result will be displayed. advance() works in a similar way to IDBCursor.continue, except that it allows you to jump multiple records at a time, not just always go onto the next record.

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 advanceResult() {
  list.textContent = '';
  const transaction = db.transaction(['rushAlbumList'], "readonly");
  const objectStore = transaction.objectStore('rushAlbumList');

  objectStore.openCursor().onsuccess = function(event) {
    const cursor = event.target.result;
    if(cursor) {
      const listItem = document.createElement('li');
      listItem.innerHTML = '<strong>' + cursor.value.albumTitle + '</strong>, ' + cursor.value.year;
      list.appendChild(listItem);
      cursor.advance(2);
    } else {
      console.log('Every other entry displayed.');
    }
  };
};

Specifications

SpecificationStatusComment
Indexed Database API 2.0
The definition of 'advance()' in that specification.
Recommendation
Indexed Database API 2.0
The definition of 'advance()' in that specification.
Recommendation

Browser compatibility

BCD tables only load in the browser

See also

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