GROUP BY和ORDER BY子句在准备声明之后（mysqli）

我有一个查询下面有一个动态where子句，但我遇到了放置GROUP BY和ORDER BY子句的问题。我不认为这是因为准备声明超出了这些条款而被触发。但它不仅仅允许我将子句行放在准备语句之上，或者它给了我一个错误，在完全不同的行中陈述未定义的问题。我的问题是GROUP BY和ORDER BY CLAUSE应该放在哪里？GROUP BY和ORDER BY子句在准备声明之后（mysqli）

CODE：

$selectedstudentanswerqry = " 
     SELECT 
     sa.StudentId, StudentAlias, StudentForename, StudentSurname, q.SessionId, 
    ... 
     FROM Student st 
    ... 
     "; 

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


     //check if POST is empty 

     // Check whether a specific student was selected 

     $p_student = empty($_POST["student"])?0:$_POST["student"]; // Now if $_POST['student'] is either 0 or empty $p_student will be 0 
    echo $p_student; 
     switch($p_student){ 
     case 0: 
      //dont' add where filters 
      break; 
     default: 
      $where[] = 'sa.StudentId = ?'; 
      $parameters[] .= $_POST["student"]; 
      $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 

      if (count($where) == 1) { 
      $selectedstudentanswerstmt->bind_param($parameterTypes, $parameters[0]); 
     } 
     else if (count($where) == 2) { 
      $selectedstudentanswerstmt->bind_param($parameterTypes, $parameters[0], $parameters[1]); 
     } 

     } 

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

来源

2013-02-18 user2056342

移动准备语句，并且如果含有bind_param（）的GROUP BY/ORDER BY子句下方语句。你有一个关闭}刚好在$selectedstudentanswerqry以上，可以移动到if (count($where) == 1)以上

来源

2013-02-18 16:38:31 Manixman

GROUP BY和ORDER BY子句在准备声明之后（mysqli）

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