Question

我有一个数据库表，其中有2个表，

问题
答案

每个问题都有多个答案

我正在尝试将所有问题和答案放在一个数组中。以下代码正常运行。我在foreach中使用for循环，如果有一点改进下面的代码，那将非常有帮助

$sql = "SELECT * FROM questions AS q LEFT JOIN answers AS a ON q.question_id=a.question_id WHERE q.question_id=a.question_id AND category_id =:category_id";
    $stmt = $this->db->conn_id->prepare($sql);
    $stmt->bindValue('category_id',$category_id, PDO::PARAM_INT);
    $stmt->execute();
    $data = $stmt->fetchAll(PDO::FETCH_ASSOC);

    foreach($data as $d){
        $qid = $d['question_id'];
        $q[$qid]['question'] = $d['question'];
        $q[$qid]['answers'][] = $d['answers'];
    }

            /*
            Checking the output, for send the $data when this function is called
    foreach($q as $id => $val){
        echo $val['question'] .'<br>';

        for($i=0; $i<4; $i++){
            echo $val['answers'][$i];
        }
    }
           */

Answer 1

我会这样做（PSEUDO CODE）：

$questions = get all questions
$answers = get all answers

$my_questions = array();

foreach ($questions as $q) {

  $my_questions[$q['id']] = array(
    'question' => $q['question'],
    'answers' => array()
  )
}

foreach ($answers as $a) {
  $my_questions[$a['question_id']]['answers'][$a['answer_id']] = $a['answer'];
}

结果如下：

[
  39 => [
    'question' => "Who am i?",
    'answers' => [
      53 => "I don't know",
      54 => "Who cares?"
    ]
  ]
]

我敢打赌，这比加入SQL中的两个表要快。也更容易处理，也无法从服务器获取任何额外数据。

显示一个到多个数组

1 个答案: