Laravel:调用未定义的方法Illuminate\Database\Eloquent\Collection::save()

Question

我基本上是想从我的表中获取特定的行并对其进行更新，但是，最终我得到了一个集合，该集合的标题中未显示错误所定义的save方法。您能告诉我下面的代码有什么问题吗？我也尝试了没有get方法的情况。但是在那种情况下，我会得到一个不同的错误。另外，在这种情况下，请让我知道是否有更好的方法从具有两个主键(userId，folderName)的表中检索行。谢谢 :)

$tempFolder =   Message_Folders::where('userId',"=",1)->where('folderName',"=",$imap_folder['name'])->get();
if($tempFolder==null){//If not existing, however in this example assume that it exists
        $tempFolder =  new Message_Folders();
        $tempFolder->userId = 1;    
        $tempFolder->folderName = $imap_folder['name'];
        }
        $tempFolder->flags = $imap_folder['status']->flags;
        $tempFolder->messages = $imap_folder['status']->messages;
        $tempFolder->recent = $imap_folder['status']->recent;
        $tempFolder->unseen = $imap_folder['status']->unseen;
        $tempFolder->uidnext = $imap_folder['status']->uidnext;
        $tempFolder->uidvalidity = $imap_folder['status']->uidvalidity;
        $tempFolder->save();

编辑1:

按照第一个答案所述更新代码后，现在出现新错误。

SQLSTATE [42S22]:找不到列:1054“where子句”中的未知列“id”(SQL:更新 message_folders设置 recent = 4， updated_at = 2014-03-08 13:34:10其中 id为null)

请引用下面的代码:(此外，如果所有值都相同，那么它将正常工作(因为实际上并未发生更新))

$tempFolder =   $this->folders->where('userId',"=",1)->where('folderName',"=",$imap_folder['name'])->first();
        if($tempFolder==null){
        $tempFolder =  new Message_Folders();
        $tempFolder->userId = 1;    
        $tempFolder->folderName = $imap_folder['name'];
        }
        $tempFolder->flags = $imap_folder['status']->flags;
        $tempFolder->messages = $imap_folder['status']->messages;
        $tempFolder->recent = 4;
        $tempFolder->unseen = $imap_folder['status']->unseen;
        $tempFolder->uidnext = $imap_folder['status']->uidnext;
        $tempFolder->uidvalidity = $imap_folder['status']->uidvalidity;

        $tempFolder->save();

编辑2:上述代码中提到的表的迁移文件的一部分:

public function up()
    {
        Schema::create('message_folders', function(Blueprint $table) {
           $table->integer('userId');
           $table->string('folderName', 200);
           $table->integer('flags');
           $table->integer('messages');
           $table->integer('recent');
           $table->integer('unseen');
           $table->integer('uidnext');
           $table->integer('uidvalidity');
           $table->timestamps();
           $table->primary(array('userId','folderName'));
        });
    }

Answer 1

下面的行使用查询生成器的get方法:

$tempFolder =   Message_Folders::where('userId',"=",1)->where('folderName',"=",$imap_folder['name'])->get();

它将从该模型中检索 所有行(当然根据位置条件过滤)。因此，您将获得一个Collection而不是模型的实例。

要从查询中检索一行，可以使用 第一种方法:

//returns a single row from the query
$tempFolder =   Message_Folders::where('userId',"=",1)->where('folderName',"=",$imap_folder['name'])->first();