IDBIndex.name - Web APIs 编辑

The name property of the IDBIndex interface contains a string which names the index.

Note:

Syntax

var indexName = IDBIndex.name;
IDBIndex.name = indexName;

Value

A DOMString specifying a name for the index.

Exceptions

There are a several exceptions which can occur when you attempt to change an index's name.

InvalidStateError

The index, or its object store, has been deleted; or the current transaction is not an upgrade transaction. You can only rename indexes during upgrade transactions; that is, when the mode is "versionchange".

TransactionInactiveError

The current transaction is not active.

ConstraintError

An index is already using the specified name.

Example

In the following example we open a transaction and an object store, then get the index lName from a simple contacts database. We then open a basic cursor on the index using IDBIndex.openCursor() — this works the same as opening a cursor directly on an IDBObjectStore using openCursor() except that the returned records are sorted based on the index, not the primary key.

The name of the index is logged to the console: it should be returned as lName.

Finally, we iterate through each record, inserting the data into an HTML table. For a complete working example, see our IndexedDB-examples demo repo (View the example live).

function displayDataByIndex() {
  tableEntry.innerHTML = '';
  var transaction = db.transaction(['contactsList'], 'readonly');
  var objectStore = transaction.objectStore('contactsList');

  var myIndex = objectStore.index('lName');
  console.log(myIndex.name);

  myIndex.openCursor().onsuccess = function(event) {
    var cursor = event.target.result;
    if(cursor) {
      var tableRow = document.createElement('tr');
      tableRow.innerHTML =   '<td>' + cursor.value.id + '</td>'
                           + '<td>' + cursor.value.lName + '</td>'
                           + '<td>' + cursor.value.fName + '</td>'
                           + '<td>' + cursor.value.jTitle + '</td>'
                           + '<td>' + cursor.value.company + '</td>'
                           + '<td>' + cursor.value.eMail + '</td>'
                           + '<td>' + cursor.value.phone + '</td>'
                           + '<td>' + cursor.value.age + '</td>';
      tableEntry.appendChild(tableRow);

      cursor.continue();
    } else {
      console.log('Entries all displayed.');
    }
  };
};

Specifications

Browser compatibility

BCD tables only load in the browser

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.)