Question

可能重复：
Errors appearing in mysqli code and call_user_func_array()

尝试使用mysqli创建动态where子句时，我遇到了很多错误：

警告：参数2到mysqli_stmt :: bind_param（）应该是一个   参考，在第319行的......中给出的值

警告：mysqli_stmt :: execute（）:( HY000 / 2031）：没有提供数据   第328行......中准备好的声明中的参数

我猜测解决问题需要做出改变但是如果两个下拉菜单中的一个不等于All或者两个都不等于All那么会发生什么它出现了错误。

下面是代码显示下拉菜单和查询（带有动态where子句），根据所选的n个选项：

PHP / mysqli的：

  function StudentAnswers()
    {


/*BELOW IS THE QUERY WHERE I AM TRYING TO RETRIEVE DATA DEPENDING ON THE ASSESSMENT CHOSEN AND
THEN DEPENDING ON OPTIONS CHOSEN IN STUDENT AND QUESTION NUMBER DROP DOWN MENU */

    $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
    ";

    // Initially empty
    $where = array('q.SessionId = ?');
    $parameters = array($_POST["session"]);
    $parameterTypes = 'i';

    // Check whether a specific student was selected
    if($_POST["student"] !== 'All') {
        $where[] = 'sa.StudentId = ?';
        $parameters[] = $_POST["student"];
        $parameterTypes .= 'i';
    }

    // Check whether a specific question was selected
    // NB: This is not an else if!
    if($_POST["question"] !== 'All') {
        $where[] = 'q.QuestionId = ?';
        $parameters[] = $_POST["question"];
        $parameterTypes .= 'i';
    }

    // If we added to $where in any of the conditionals, we need a WHERE clause in
    // our query
    if(!empty($where)) {
        $selectedstudentanswerqry .= ' WHERE ' . implode(' AND ', $where);
        global $mysqli;
        $selectedstudentanswerstmt=$mysqli->prepare($selectedstudentanswerqry);
        // You only need to call bind_param once
            call_user_func_array(array($selectedstudentanswerstmt, 'bind_param'),
            array_merge(array($parameterTypes), $parameters)); //LINE 319 ERROR 1
    }

//Add group by and order by clause to query
    $selectedstudentanswerqry .= "
      GROUP BY sa.StudentId, q.QuestionId
      ORDER BY StudentAlias, q.SessionId, QuestionNo
    ";

    // get result and assign variables (prefix with db)
    $selectedstudentanswerstmt->execute(); //LINE 328 ERROR 2

//bind database fields $selectedstudentanswerstmt->bind_result($detailsStudentAlias,$detailsStudentForename,$detailsStudentSurname,$detailsSessionId,$detailsQuestionNo, 
    $detailsQuestonContent,$detailsOptionType,$detailsNoofAnswers,$detailsAnswer,$detailsReplyType,$detailsQuestionMarks,$detailsStudentAnswer,$detailsResponseTime,
    $detailsMouseClick,$detailsStudentMark); //LINE 331 ERROR 3

//store results retrieved
    $selectedstudentanswerstmt->store_result(); //LINE 332 ERROR 4

//count number of rows retrieved
    $selectedstudentanswernum = $selectedstudentanswerstmt->num_rows();     

//output query
    echo "$selectedstudentanswerqry";

    }

    ?>

使用call_user_func_array（）导致错误

0 个答案: