Question

用户有多个问题，有多个用户的问题问题有多个答案用户有多个答案关系在模型中设定。

表：

questions --> id   question
answers --> id q_id user_id answer
users --> id email username
question_user --> user_id q_id

我如何能够检索特定用户对特定问题的回答。

通过这种方式，我可以得到用户的答案和问题：

$users=User::where(['id'=>1])->with('questions','answers')->get(); 
foreach($users as $user)
{
    foreach($user->questions as $question)
    {
        echo "<pre>";print_r($question->question);                      
    }

    foreach($user->answers as $answer)
    {
        echo "<pre>";print_r($answer->answer);          
    }
}

这样我就可以得到用户的问题，但问题的所有答案都可以。

$users=User::where(['id'=>1])->with('questions','answers')->get(); 
        foreach($users as $user)
        {
            foreach($user->questions as $question)
            {
                echo "<pre>";print_r($question->question);  
                foreach($question->answers as $answer)
                {
                    echo "<pre>";print_r($answer->answer);
                }                   
            }
        }

但是我遇到了特定用户的问题和特定用户回答问题的麻烦。这样一来 我需要的结果

user id=1.
question 1
answer by user id 1.
question 2
answer by user id 1
...



 user id=2.
 question 1
 answer by user id 2.
 question 2
 answer by user id 2
   ...

Answer 1

试试这个

foreach($users as $user)
    {
        foreach($user->questions as $question)
        {
            echo "<pre>";print_r($question->question);  
            foreach($question->answers as $answer)
            {
                  echo "<pre>";print_r($answer->filter(function ($answer) use ($user) {
                    return $answer->user_id== $user->id;
                });
            }                   
        }
    }

Answer 2

你去了

// User model
public function answeredQuestions()
{
  return $this->belongsToMany(Question::class, 'answers', 'user_id', 'question_id');
}

// then
$user->answeredQuestions()->find($question_id)->pivot->answer;

// or to make it 'safe' - no Trying to get property on non-object if no answer is found
data_get($user->answeredQuestions()->find($question_id), 'pivot.answer');

Laravel检索数据的多种关系

2 个答案: