IDBIndex.multiEntry

The multiEntry read-only property of the IDBIndex interface returns a boolean value that affects how the index behaves when the result of evaluating the index's key path yields an array.

This is decided when the index is created, using the IDBObjectStore.createIndex method. This method takes an optional options parameter whose multiEntry property is set to true/false.

Note:

This feature is available in Web Workers.

Syntax

var isMultiEntry = myIndex.multiEntry;

Value

A Boolean:

Value Effect
true There is one record in the index for each item in an array of keys.
false There is one record for each key that is an array.

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 ObjectStore using IDBObjectStore.openCursor except that the returned records are sorted based on the index, not the primary key.

The multi-entry status of the index is logged to the console: it should be returned as false.

Finally, we iterate through each record, and insert 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.multiEntry);

  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