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ドロップダウン メニューから選択したオプションに応じて、正しい WHERE 句をコンパイルする動的な WHERE 句を作成しようとしています。しかし、私はそれを正しくやっているとは思いません。

まず最初に、デフォルトの WHERE 句が必要です。ドロップダウン メニューからどのオプションが選択されても、選択されているかどうかをチェックする WHERE 句が存在する必要がありSessionIdます。SessionId = ?

次に、ドロップダウン メニューから選択したオプションに応じて、WHERE 句の他のフィールドをコンパイルします。と の 2 つのドロップダウン メニューがありStudentsますQuestions。考えられる結果は次のとおりです。

Student selected != 'All': 追加StudentId= ? WHERE 句内 : = ?をStudent selected == 'All'削除します。StudentIdWHERE 句から : = ?Question selected != 'All'を追加します。QuestionIdWHERE 句内 : = ?をQuestion selected == 'All'削除します。QuestionIdWHERE句から

私の質問は、これをどのように設定できますか?

以下は私が現在持っているものです：

        if(isset($_POST['answerSubmit'])) // we have subbmited the third form
        {

    $selectedstudentanswerqry = "
    SELECT
    StudentAlias, StudentForename, StudentSurname, q.SessionId, QuestionNo, QuestionContent, o.OptionType, q.NoofAnswers, GROUP_CONCAT( DISTINCT Answer
    ORDER BY Answer SEPARATOR ',' ) AS Answer, r.ReplyType, QuestionMarks, 
    GROUP_CONCAT(DISTINCT StudentAnswer ORDER BY StudentAnswer SEPARATOR ',') AS StudentAnswer, ResponseTime, MouseClick, StudentMark
    FROM Student s
    INNER JOIN Student_Answer sa ON (s.StudentId = sa.StudentId)
    INNER JOIN Student_Response sr ON (sa.StudentId = sr.StudentId)
    INNER JOIN Question q ON (sa.QuestionId = q.QuestionId)
    INNER JOIN Answer an ON q.QuestionId = an.QuestionId
    LEFT JOIN Reply r ON q.ReplyId = r.ReplyId
    LEFT JOIN Option_Table o ON q.OptionId = o.OptionId
    ";

    if ($_POST['student'] != 'All'){
    $selectedstudentanswerqry .= "
    WHERE (SessionId = ? AND StudentId = ?)
    ";
    }

    if ($_POST['question'] != 'All'){
    $selectedstudentanswerqry .= "
    WHERE (SessionId = ? AND QuestionId = ?)
    ";
    }

    $selectedstudentanswerqry .= "
    GROUP BY sa.StudentId, q.QuestionId
    ORDER BY StudentAlias, q.SessionId, QuestionNo
    ";

    global $mysqli;
    $selectedstudentanswerstmt=$mysqli->prepare($selectedstudentanswerqry);
    if ($_POST['student'] != 'All'){
    // You only need to call bind_param once
    $selectedstudentanswerstmt->bind_param("ii",$_POST["session"],$_POST["student"]);
    }
    if ($_POST['question'] != 'All'){
    // You only need to call bind_param once
    $selectedstudentanswerstmt->bind_param("ii",$_POST["session"],$_POST["question"]);
    }
    // get result and assign variables (prefix with db)
    $selectedstudentanswerstmt->execute(); 
    $selectedstudentanswerstmt->bind_result($detailsStudentAlias,$detailsStudentForename,$detailsStudentSurname,$detailsSessionId,$detailsQuestionNo, 
    $detailsQuestonContent,$detailsOptionType,$detailsNoofAnswers,$detailsAnswer,$detailsReplyType,$detailsQuestionMarks,$detailsStudentAnswer,$detailsResponseTime,
    $detailsMouseClick,$detailsStudentMark);
    $selectedstudentanswerstmt->store_result();
    $selectedstudentanswernum = $selectedstudentanswerstmt->num_rows();     

    }


    ?>
4

2 に答える 2

4

where配列を構築してみてください

$where = array();


if ((int) $studentID >0) {
   $where[] = " studentID = '{$studentID}' ";
}
if ((int) $QuestionId  >0) {
   $where[] = " QuestionId  = '{$QuestionId }' ";
}

そして最後に AND ステートメントで $where を内破する

if (!empty($where)) 
$query['where'] = ' WHERE '. implode(' AND ', $where);

それはただの方法です。このコードはデバッグしませんでした。

于 2013-01-26T19:22:10.173 に答える
0

あなたのケース:

- Student selected != 'All' : Add StudentId = ? in WHERE clause 
- Student selected == 'All' : Remove StudentId = ? from WHERE clause 
- Question selected != 'All' : Add QuestionId = ? in WHERE clause 
- Question selected == 'All' : Remove QuestionId = ? from WHERE clause

<?php
$selectedstudentanswerqry = "WHERE SessionId = ? ";
if ($_POST['student'] != 'All'){
 $selectedstudentanswerqry .= " and StudentId = ? ";
}
else{
/*
$selectedstudentanswerqry .= "
//what is condition for if student == all ?
";
*/
}
if ($_POST['question'] != 'All'){
  $selectedstudentanswerqry .= " and QuestionId = ? ";
}
else{
}
?>

それを考慮してください

student = 1 then:

if student != All = true
if question != AA = true

student = All
if student != All = false
if question != AA = true

question = 1 
if student != All = true
if question != AA = true

question = All
if student != All = true
if question != AA = false

これが欲しいかどうかを確認しますか？違うと思う。

    //case1
    if ($_POST['student'] != 'All'){
      $selectedstudentanswerqry .= "
      WHERE (SessionId = ? AND StudentId = ?)
      ";
    }

    //case2
    if ($_POST['question'] != 'All'){
      //case 2.1
      if ($_POST['student'] != 'All'){
        $selectedstudentanswerqry .= "
         and  (QuestionId = ?)
        ";
      }
      //case 2.2
      else{
        $selectedstudentanswerqry .= "
        WHERE (SessionId = ? AND QuestionId = ?)
        ";
      }

    }
/*
    testing
    1- student != All, question != All
    case1: true
    case1: result: $selectedstudentanswerqry = WHERE (SessionId = ? AND StudentId = ?)
    case2 : true
    case 2.1: true
    case2.1 result:  $selectedstudentanswerqry .= and  (QuestionId = ?)

    2- student != All question = All
    case1: true
    case1: result: $selectedstudentanswerqry = WHERE (SessionId = ? AND StudentId = ?)
    case2: false

    3- student = All question != All
    case1: false
    case2: true
    case2.1: false
    case2.2: true
    case2.2 result: $selectedstudentanswerqry = WHERE (SessionId = ? AND QuestionId = ?)

    4- student = All question = All
    case1: false
    case2: false
*/
于 2013-01-26T18:56:21.380 に答える