更新 indexedDB

Question

您好，我正在尝试更新记录 indexdb。我想实现一个通用方法，允许我升级到任何字段。

为此，我有一个函数可以返回我需要的记录。

function getObjectStoreClienteDB(clave,valor){
    //Ahora recogeremos los datos de nuestro almacén "Productos"
    var transaction = db.transaction(["customers"], "readwrite");
    var objectStore = transaction.objectStore("customers");

    var index = objectStore.index(clave);
    var singleKeyRange = IDBKeyRange.only(valor);

    // To use one of the key ranges, pass it in as the first argument of openCursor()/openKeyCursor()

    return  index.openCursor(singleKeyRange);
} 

另一个更新返回的记录

function updateClienteDB(clave,valor,newvalor){
    console.log("updateClienteDB ... clave: "+clave+" valor: "+valor+" newvalor: "+newvalor);
    var objectStore = db.transaction(["customers"], "readwrite").objectStore("customers");

    request = getObjectStoreClienteDB("name",valor);

    request.onsuccess = function(event) {
      // Get the old value that we want to update
      var data = request.result;

      // update the value(s) in the object that you want to change
      if(clave=="name")
        data.name = newvalor;
       else if(clave=="email")
        data.email = newvalor;
       else if(clave=="matricula")
        data.matricula = newvalor;
       else if(clave=="telefono")
        data.telefono = newvalor;

      // Put this updated object back into the database.
      var requestUpdate = objectStore.put(data);
       requestUpdate.onerror = function(event) {
          console.log("addCliente ..."+name+" "+email +" "+ event.target.errorCode);
       };
       requestUpdate.onsuccess = function(event) {
            console.log("All done!");
       };
    };
}

在该行中： var requestUpdate = objectStore.put(data);

错误： 未捕获的 TransactionInactiveError：无法在 'IDBObjectStore' 上执行 'put'：事务已完成。

Answer 1

尝试使用相同的读写事务。看起来您在两个地方调用 db.transaction(...) 。然后，您尝试在不同事务的上下文中更新链接到不同事务的对象存储。结果是其中一个事务完成（其生命周期结束），可能是因为它超时了，因为它没有检测到任何已注册的请求。 objectStore 变量存在于提前完成的事务的生命周期内，因此您会收到事务完成错误。

这很容易解决。您只需要在其生命周期结束之前在同一事务上注册一个新请求（put 请求）。为此，您可以 (a) 内联语句 request = getObjectStoreClienteDB("name",valor); 以便它附加到同一个事务实例，或者 (b) 将事务实例存储在单独的变量中并在两个调用中引用它。

例如，以下代码是对您使用单个事务的修改：

// this function was changed, it now takes an active transaction as its first argument.

function getObjectStoreClienteDB(transaction, clave,valor){
  //Ahora recogeremos los datos de nuestro almacén "Productos"

  // this was changed. instead of creating a new transaction we just reference the
  // transaction instance passed to this function
  var objectStore = transaction.objectStore("customers");

  var index = objectStore.index(clave);
  var singleKeyRange = IDBKeyRange.only(valor);

  // To use one of the key ranges, pass it in as the first argument of openCursor()/openKeyCursor()

  return  index.openCursor(singleKeyRange);
} 

function updateClienteDB(clave,valor,newvalor){
  console.log("updateClienteDB ... clave: "+clave+" valor: "+valor+" newvalor: "+newvalor);

  // this line was added. we create the transaction here, once
  var transaction = db.transaction(["customers"], "readwrite");

  // this line was changed, we simply reference the transaction instance here instead of 
  // creating a second transaction
  var objectStore = transaction.objectStore("customers");

  // this line was  changed, we pass in the one active transaction instance to the function
  // now instead of having the function create its own transaction
  request = getObjectStoreClienteDB(transaction, "name",valor);

  request.onsuccess = function(event) {
    // Get the old value that we want to update
    var data = request.result;

    // update the value(s) in the object that you want to change
    if(clave=="name")
      data.name = newvalor;
    else if(clave=="email")
      data.email = newvalor;
    else if(clave=="matricula")
      data.matricula = newvalor;
    else if(clave=="telefono")
      data.telefono = newvalor;

    // Put this updated object back into the database.

    // this line now works. objectStore is attached to our 1 transaction that is still 'alive' 
    // because it gets registered 'in time' (before transaction finishes due to timeout due 
    // to no additional requests registered in allowed time window).
    var requestUpdate = objectStore.put(data);


    requestUpdate.onerror = function(event) {
      console.log("addCliente ..."+name+" "+email +" "+ event.target.errorCode);
    };
    requestUpdate.onsuccess = function(event) {
      console.log("All done!");
    };
  };
}

而且，为了清楚起见，这里是第二个例子。它使用调用者的事务重新创建对对象存储的引用，而不是交叉引用附加到不同事务的对象存储：

function updateClienteDB(clave,valor,newvalor){
  console.log("updateClienteDB ... clave: "+clave+" valor: "+valor+" newvalor: "+newvalor);
  var objectStore = db.transaction(["customers"], "readwrite").objectStore("customers");

  request = getObjectStoreClienteDB("name",valor);

  request.onsuccess = function(event) {
    // Get the old value that we want to update
    var data = request.result;

    // update the value(s) in the object that you want to change
    if(clave=="name")
      data.name = newvalor;
    else if(clave=="email")
      data.email = newvalor;
    else if(clave=="matricula")
      data.matricula = newvalor;
    else if(clave=="telefono")
      data.telefono = newvalor;

    // Put this updated object back into the database.

    // the following line is changed so that it works. 
    //var requestUpdate = objectStore.put(data);

    var theOtherTransactionThatIsStillAlive = event.transaction;
    var objectStoreFromValidTransaction = theOtherTransactionThatIsStillAlive.objectStore('customers');

    var requestUpdate = objectStoreFromValidTransaction.put(data);

    requestUpdate.onerror = function(event) {
      console.log("addCliente ..."+name+" "+email +" "+ event.target.errorCode);
    };
    requestUpdate.onsuccess = function(event) {
      console.log("All done!");
    };
  };
}