致命錯誤導致沒有結果出現（mysqli的）

Question

我得到這個錯誤在我的劇本，我認爲是造成搜索欄不工作：

Fatal error: Call to a member function bind_param() on a non-object in /web/stud/xxx/Mobile_app/previousquestions.php on line 89.

線它指向的就是這條線：

$stmt->bind_param("s",$each);  

需要做什麼才能解決這個錯誤？此時，錯誤導致用戶在搜索欄內提交內容後不會顯示任何結果。

<?php 

     //connect to db 

      $questioncontent = (isset($_POST['questioncontent'])) ? $_POST['questioncontent'] : ''; 

     ?> 

     <?php 

     if (isset($_GET['searchQuestion'])) { 

     $searchquestion = $questioncontent; 
     $terms = explode(" ", $searchquestion); 
$parameters = array(); 

     $questionquery = " 
     SELECT q.QuestionId, q.QuestionContent, o.OptionType, q.NoofAnswers, GROUP_CONCAT(an.Answer ORDER BY an.Answer SEPARATOR ' ') AS Answer, r.ReplyType, 
       q.QuestionMarks 
      FROM Answer an 
      INNER JOIN Question q ON q.AnswerId = an.AnswerId 
      JOIN Reply r ON q.ReplyId = r.ReplyId 
      JOIN Option_Table o ON q.OptionId = o.OptionId 

         WHERE "; 

     $i=0; 
     foreach ($terms as $each) {  
      $i++;   

      if ($i == 1){   
       $questionquery .= "q.QuestionContent LIKE ?";  
       } else {   
        $questionquery .= "OR q.QuestionContent LIKE ?";  
        } 
        } 

        $questionquery .= "GROUP BY q.QuestionId, q.SessionId ORDER BY "; $i = 0; foreach ($terms as $each) {  
         $i++;  

      if ($i != 1)   
      $questionquery .= "+";  
      $questionquery .= "IF(q.QuestionContent LIKE ?,1,0)"; 
      } 

      $questionquery .= " DESC "; 

      $stmt=$mysqli->prepare($questionquery);  
    $parameters[] = ($each) 
    $stmt->execute($parameters); 
      $stmt->bind_result($dbQuestionId,$dbQuestionContent,$dbOptionType,$dbNoofAnswers,$dbAnswer,$dbReplyType,$dbQuestionMarks); 
      $questionnum = $stmt->num_rows(); 

     } 

    ?> 

Answer 1

這意味着$語句變量沒有被正確設置 - 我認爲你需要的LIKE ?線後的空間，因爲你後馬上concatening GROUP BY。

您需要檢查您生成的SQL語句是否正確，以及數據庫連接是否正常。