Question

我正在尝试进行测验，并使用以下内容来比较结果，它似乎工作和输出一次，但就是这样，我不会再处理任何记录，即使有两个问题在测验，所以它应该输出正确，正确或正确，不正确等。

          <?php
    // Make a MySQL Connection
    // Construct our join query
    $query = "SELECT * FROM itsnb_chronoforms_data_answerquiz a, itsnb_chronoforms_data_createquestions
    q WHERE a.quizID='$quizID' AND a.userID='$userID' and q.quizID=a.quizID and
    a.quizselectanswer = q.correctanswer" or die("MySQL ERROR: ".mysql_error());

    $result = mysql_query($query) or die(mysql_error());


    // Print out the contents of each row into a table 
    while($row = mysql_fetch_array($result)){
        if ($row['correctanswer'] == $row['quizselectanswer']){
            echo 'CORRECT';}
            else { echo 'INCORRECT';
            }

        echo "<br />";
    }
    ?>

编辑＆gt;＆gt;＆gt;＆gt;＆gt;＆gt;＆gt;＆gt;＆gt;＆gt;＆gt;＆gt;＆gt;＆gt;＆gt;＆gt;＆gt;＆gt;＆gt;＆gt;＆gt;＆gt;＆gt;＆gt;＆gt;＆gt;＆gt;＆gt;＆gt;＆gt; ＆GT;＆GT;＆GT;＆GT;＆GT;＆GT;＆GT;＆GT;＆GT;＆GT;＆GT;＆GT;＆GT;＆GT;＆GT;＆GT;＆GT;＆GT;＆GT;＆GT;＆GT;＆GT;＆GT;＆GT;＆GT; ＆GT;＆GT;＆GT;＆GT;＆GT;＆GT;＆GT;＆GT;＆GT;＆GT;

表结构如下＆gt;＆gt;

itsnb_chronoforms_data_answerquiz cf_id，cf_uid，cf_created，cf_modified，cf_ipaddress，cf_user_id，questionID，quizselectanswer，quizID，userID

itsnb_chronoforms_data_createquestions cf_id，cf_uid，cf_created，cf_modified，cf_ipaddress，cf_user_id，quizID，questionID，quizquestion，quizanswer1，quizanswer2，quizanswer3，quizanswer4，questionformat，correctanswer

Answer 1

当你删除selectanswer = correctanswer条件时，你得到四个答案（这确实不是你想要的，因为你想要获取正确和错误的答案），因为你没有关联答案ID。

$query = "SELECT * FROM itsnb_chronoforms_data_answerquiz a, itsnb_chronoforms_data_createquestions
q WHERE a.quizID='$quizID' AND a.userID='$userID' and q.quizID=a.quizID and
a.quizselectanswer = q.correctanswer" or die("MySQL ERROR: ".mysql_error());

应该是：

$query = "SELECT * FROM itsnb_chronoforms_data_answerquiz a, itsnb_chronoforms_data_createquestions
q WHERE a.quizID='$quizID' AND a.userID='$userID' and q.quizID=a.quizID and
a.questionID = q.questionID" or die("MySQL ERROR: ".mysql_error());

你在没有这个条件的情况下得到了questionID的交叉产品。您看到的四条记录（如果questionID为1和2）：

a.questionID = 1且q.questionID = 1
a.questionID = 1且q.questionID = 2（不要这样）
a.questionID = 2且q.questionID = 1（或此）
a.questionID = 2且q.questionID = 2

Join + While循环只输出一个结果

1 个答案: