如何在 laravel 5 中使用 Eloquent 更新数据透视表

Question

我是 laravel 的新手。我正在开发一个 laravel 5 应用程序，但我被困在这里。我有 2 个这样的模型：

class Message extends Eloquent{

    public function user()
    {
        return $this->belongsTo('App\User', 'from');
    }

    public function users()
    {
        return $this->belongsToMany('App\User')->withPivot('status');
    }
}

class User extends Eloquent {

    public function messages()
    {
        return $this->hasMany('App\Message', 'from');
    }

    public function receive_messages() {
        return $this->belongsToMany('App\Message')->withPivot('status');
    }
}

Message 和 User 之间存在多对多关系，为我提供了这样的数据透视表：

Table Name: message_user
Colums:
message_id
user_id
status

我有一个这样的 SQL 查询：

update message_user
set status = 1
where user_id = 4 and message_id in (select id from messages where message_id = 123)

如何将此查询转换为 laravel 等效项？

Answer 1

您可以使用one of these two functions、sync() attach()，简而言之，Sync 将获取数组作为其第一个参数并将其与数据透视表同步（删除并添加在您的array) 这意味着如果您在联结表中获得了 3,2,1 的值，并与 3,4,2 的值同步传递，同步将自动删除值 1 并为您添加值 4。其中 Attach 将采用单个 ID 值

GIST：如果您想向连接表添加额外的值，请将其作为第二个参数传递给 sync()，如下所示：

$message = Messages::find(123);
$user = User::find(4);

// using attach() for single message
$user->message()->attach($message->id, [
    'status' => 1
]);



$message2 = Messages::find(456); // for testing

// using sync() for multiple messages
$user->message()->sync([
    $message->id => [
        'status' => 1
    ],
    $message2->id => [
        'status' => 1
    ],
]);

Answer 2

这是一个如何更新数据透视表列的小例子

    $query = Classes::query();
    $query = $query->with('trainees')
                   ->where('user_id', Auth::id())
                   ->find($input['classId']);

    foreach ($query->trainees as $trainee) {
       $trainee->pivot->status = 1 //your column;
       $trainee->pivot->save();
    }

注意：确保你的关系数据必须在一个数组中 希望它对你有帮助:) 快乐编码

Answer 3

Laravel 5.8

首先，通过将withPivot 方法链接到您的belongsToMany 来允许您的数据透视列可搜索

从我自己的代码中复制以节省时间

// I have 3 columns in my Pivot table which I use in a many-to-many and one-to-many-through scenarios

$task = $user->goalobjectives()->where(['goal_objective_id'=>$goal_objective_id,'goal_obj_add_id'=>$goal_obj_add_id])->first(); //get the first record

$task->pivot->goal_objective_id = $new; //change your col to a new value

$task->pivot->save(); //save

需要注意的是，您的数据透视表需要有一个主要的 'id' 键。

如果你不想这样，那么你可以尝试以下方法：

$tasks=$user->posts()->where(['posts_id'=>$posts_id,'expires'=>true])->get()->pluck('id'); // get a collection of your pivot table data tied to this user

$key=join(",",array_keys($tasks->toArray(),$valueYouWantToRemove));

$tasks->splice($key,1,$newValueYouWantToInsert);

$c = array_fill(0,$tasks->count(),['expires'=>true]); //make an array containing your pivot data

$newArray=$tasks->combine($c) //combine the 2 arrays as keys and values

$user->posts()->sync($newArray); //your pivot table now contains only the values you want

7 月 4 日更新更新至以上 sn-p。

//Ideally, you should do a check see if this user is new
//and if he already has data saved in the junction table
//or are we working with a brand new user

$count = $user->goalobjectives->where('pivot.goal_obj_add_id',$request->record)->count();

//if true, we retrieve all the ids in the junction table 
//where the additional pivot column matches that which we want to update

if($count) {

$ids = $user->goalobjectives->where('pivot.goal_obj_add_id',$request->record)->pluck('id');

//convert to array

$exists = $ids->toArray();

//if user exists and both saved and input data are exactly the same
//there is no need
//to update and we redirect user back

if(array_sum($inputArray) == array_sum($exists)) {

//redirect user back

}

//else we update junction table with a private function
//called 'attachToUser'

$res = $this->attachToUser($user, $inputArray, $ids, $request->record);

}//end if

elseif(!$count) {

//we are working with a new user
//we build an array. The third pivot column must have equal rows as
//user input array

$fill = array_fill(0,count($inputArray),['goal_obj_add_id'=>$request->record]);

//combine third pivot column with user input

$new = array_combine($inputArray,$fill);

//junction table updated with 'user_id','goal_objective_id','goal_obj_add_id'

$res = $user->goalobjectives()->attach($new);

//redirect user if success

}

//our private function which takes care of updating the pivot table

private function attachToUser(User $user, $userData, $storedData, $record) {

//find the saved data which must not be deleted using intersect method

$intersect = $storedData->intersect($userData);

if($intersect->count()) {

//we reject any data from the user input that already exists in the database

$extra = collect($userData)->reject(function($value,$key)use($intersect){

return in_array($value,$intersect->toArray());

});

//merge the old and new data

$merge = $intersect->merge($extra);

//same as above we build a new input array

$recArray = array_fill(0,$merge->count(),['goal_obj_add_id'=>$record]);

//same as above, combine them and form a new array

$new = $merge->combine($recArray);

//our new array now contains old data that was originally saved
//so we must remove old data linked to this user
// and the pivot record to prevent duplicates

$storedArray = $storedData->toArray();

$user->goalobjectives()->wherePivot('goal_obj_add_id',$record)->detach($storedArray);

//this will save the new array without detaching
//other data previously saved by this user

$res = $user->goalobjectives()->wherePivot('goal_obj_add_id',$record)->syncWithoutDetaching($new);

}//end if

//we are not working with a new user
//but input array is totally different from saved data
//meaning its new data

elseif(!$intersect->count()) {

$recArray = array_fill(0,count($userData),['goal_obj_add_id'=>$record]);

$new = $storedData->combine($recArray);

$res = $user->goalobjectives()->wherePivot('goal_obj_add_id',$record)->syncWithoutDetaching($new);

}

//none of the above we return false

return !!$res;

}//end attachToUser function

这适用于没有主要自动增量 ID 的数据透视表。如果没有自动增量 ID，用户无法通过直接访问来更新、插入、删除数据透视表中的任何行。

Answer 4

下面的代码解决了我的问题：

$messages  = Message::where('message_id', $id)->get();
foreach($messages as $message)
   $message->users()->updateExistingPivot($user, array('status' => 1), false);

Answer 5

要更新您的数据透视表，您可以使用 updateExistingPivot 方法。