IDBObjectStore.keyPath

句法

var mykeyPath = objectStore.keyPath;

Value

任何类型。

例子

在下面代码片段中，我们在数据库里打开了一个可读写的事务（transaction），并且用add()向一个objectStore中添加了一些数据。在objectStore被创建之后，我们在console中打印了objectStore.keyPath的值。想查看完整的例子，请查看我们的To-do Notifications应用（查看在线例子）。

// Let us open our database
var DBOpenRequest = window.indexedDB.open("toDoList", 4);

DBOpenRequest.onsuccess = function(event) {
  note.innerHTML += '<li>Database initialised.</li>';
    
  // store the result of opening the database in the db variable.
  // This is used a lot below
  db = DBOpenRequest.result;
    
  // Run the addData() function to add the data to the database
  addData();
};

function addData() {
  // Create a new object ready to insert into the IDB
  var newItem = [ { taskTitle: "Walk dog", hours: 19, minutes: 30, day: 24, month: "December", year: 2013, notified: "no" } ];

  // open a read/write db transaction, ready for adding the data
  var transaction = db.transaction(["toDoList"], "readwrite");

  // report on the success of the transaction completing, when everything is done
  transaction.oncomplete = function(event) {
    note.innerHTML += '<li>Transaction completed.</li>';
  };

  transaction.onerror = function(event) {
  note.innerHTML += '<li>Transaction not opened due to error. Duplicate items not allowed.</li>';
  };

  // create an object store on the transaction
  var objectStore = transaction.objectStore("toDoList");
  console.log(objectStore.keyPath);

  // Make a request to add our newItem object to the object store
  var objectStoreRequest = objectStore.add(newItem[0]);

  objectStoreRequest.onsuccess = function(event) {
    // report the success of our request
    note.innerHTML += '<li>Request successful.</li>';
  };
};

规范

浏览器兼容性

相关内容

• 使用 IndexedDB
• 开始学习事务 transactions: IDBDatabase
• 使用事务 transactions: IDBTransaction
• 值域range的使用: IDBKeyRange
• 检索、修改: IDBObjectStore
• 使用游标: IDBCursor
• 相关例子: To-do Notifications (view example live.)