php - 在每个 div 选项卡中显示一个随机测试问题

Question

我是 php 新手，正在从事技能测试项目。我的目标是在每个 div 选项卡中显示 mysql 数据库中的一个随机问题，而不重复问题。我当前的问题是每个选项卡中都显示相同的问题。我希望有人能帮助我解决这个问题。非常感谢!

这是我的代码:

         <?php   
           $servername = "localhost";
           $username = "root";
           $password = "";
           $dbname = "palo";
           $conn= mysqli_connect($servername, $username, $password, $dbname);
           if(!$conn){
             die("Connection failed: ". mysqli_connect_error());
           }
           $sql = "SELECT test_id, question, optiona, optionb, optionc, optiond FROM tquestions ORDER BY RAND() LIMIT 1";      
           $result = mysqli_query ($conn, $sql); // Run the query
           if (!$result) {
              printf("Error: %s\n", mysqli_error($conn));
           exit();
           }
        ?>

        <script>
        function openTab(evt, tabName) {
            var i, tabcontent, tablinks;
            tabcontent = document.getElementsByClassName("tabcontent");
            for (i = 0; i < tabcontent.length; i++) {
                tabcontent[i].style.display = "none";
            }
            tablinks = document.getElementsByClassName("tablinks");
            for (i = 0; i < tablinks.length; i++) {
                tablinks[i].className = tablinks[i].className.replace(" active", "");
            }
            document.getElementById(tabName).style.display = "block";
            evt.currentTarget.className += " active";
        }
        document.getElementById("defaultOpen").click();
        </script>

        <div class="tab">
          <button class="tablinks" onclick="openTab(event, 'q1')" id="defaultOpen">1</button>
          <button class="tablinks" onclick="openTab(event, 'q2')">2</button>
          <button class="tablinks" onclick="openTab(event, 'q3')">3</button>
        </div>            

        <?php if (!empty($_SESSION['msg'])) { ?>
            <div class="alert alert-info"><?php echo $_SESSION['msg']; ?></div>
        <?php } ?>

        <div id="q1" class="tabcontent">
            <table class="table table-hover">
            <tbody>
                <?php if (mysqli_num_rows($result) > 0): ?>
                    <?php foreach ($result as $results):?>
                        <tr class="form-group">   
                            <h3 name="ques[<?php echo $test_id;?>]" style="text-indent: 40px;"> <?php echo $results['question']; ?> </h3>
                        </tr>
                        <tr class="form-group">
                            <label class="radio-inline" style="text-indent: 70px; font-size: 18px;">
                                &nbsp;&nbsp;<input style="font-size: 18px;" type="radio" name="ans[<?php echo $results['test_id'];?>" value="<?php echo $results['optiona'];?>"><?php echo $results['optiona'];?> 
                            </label>
                            <br>
                            <label class="radio-inline" style="text-indent: 70px; font-size: 18px;">
                                 &nbsp;&nbsp;<input style="font-size: 18px;" type="radio" name="ans[<?php echo $results['test_id'];?>" value="<?php echo $results['optionb'];?>"><?php echo $results['optionb'];?> 
                            </label>
                            <br>
                            <label class="radio-inline" style="text-indent: 70px; font-size: 18px;">
                                 &nbsp;&nbsp;<input style="font-size: 18px;" type="radio" name="ans[<?php echo $results['test_id'];?>" value="<?php echo $results['optionc'];?>"><?php echo $results['optiond'];?> 
                            </label>
                            <br>
                            <label class="radio-inline" style="text-indent: 70px; font-size: 18px;">
                                 &nbsp;&nbsp;<input style="font-size: 18px;" type="radio" ame="ans[<?php echo $results['test_id'];?>" value="<?php echo $results['optiond'];?>"><?php echo $results['optiond'];?>
                            </label>
                            <br>
                        </tr>
                    <?php endforeach ?>
                <?php endif ?>
            </tbody>
            </table>
        </div>

        <div id="q2" class="tabcontent">
            <table class="table table-hover">
            <tbody>
                <?php if (mysqli_num_rows($result) > 0): ?>
                    <?php foreach ($result as $results):?>
                        <tr class="form-group">   
                            <h3 name="ques[<?php echo $test_id;?>]" style="text-indent: 40px;"> <?php echo $results['question']; ?> </h3>
                        </tr>
                        <tr class="form-group">
                            <label class="radio-inline" style="text-indent: 70px; font-size: 18px;">
                                &nbsp;&nbsp;<input style="font-size: 18px;" type="radio" name="ans[<?php echo $results['test_id'];?>" value="<?php echo $results['optiona'];?>"><?php echo $results['optiona'];?> 
                            </label>
                            <br>
                            <label class="radio-inline" style="text-indent: 70px; font-size: 18px;">
                                 &nbsp;&nbsp;<input style="font-size: 18px;" type="radio" name="ans[<?php echo $results['test_id'];?>" value="<?php echo $results['optionb'];?>"><?php echo $results['optionb'];?> 
                            </label>
                            <br>
                            <label class="radio-inline" style="text-indent: 70px; font-size: 18px;">
                                 &nbsp;&nbsp;<input style="font-size: 18px;" type="radio" name="ans[<?php echo $results['test_id'];?>" value="<?php echo $results['optionc'];?>"><?php echo $results['optiond'];?> 
                            </label>
                            <br>
                            <label class="radio-inline" style="text-indent: 70px; font-size: 18px;">
                                 &nbsp;&nbsp;<input style="font-size: 18px;" type="radio" ame="ans[<?php echo $results['test_id'];?>" value="<?php echo $results['optiond'];?>"><?php echo $results['optiond'];?>
                            </label>
                            <br>
                        </tr>
                    <?php endforeach ?>
                <?php endif ?>
            </tbody>
            </table>
        </div>

Answer 1

当您使用时，您对查询的排序是正确的

ORDER BY RAND()

但是你需要根据你想要达到的总数来限制结果，例如

limit 0, 2

即使您使用的是 foreach，您也使用相同的记录。您需要迭代记录，如下所示:

     <?php   
       $servername = "localhost";
       $username = "root";
       $password = "";
       $dbname = "palo";
       $conn= mysqli_connect($servername, $username, $password, $dbname);
       if(!$conn){
         die("Connection failed: ". mysqli_connect_error());
       }
       $sql = "SELECT test_id, question, optiona, optionb, optionc, optiond FROM tquestions ORDER BY RAND() LIMIT 1";      
       $result = mysqli_query ($conn, $sql); // Run the query
       if (!$result) {
          printf("Error: %s\n", mysqli_error($conn));
       exit();
       }
    ?>

    <script>
    function openTab(evt, tabName) {
        var i, tabcontent, tablinks;
        tabcontent = document.getElementsByClassName("tabcontent");
        for (i = 0; i < tabcontent.length; i++) {
            tabcontent[i].style.display = "none";
        }
        tablinks = document.getElementsByClassName("tablinks");
        for (i = 0; i < tablinks.length; i++) {
            tablinks[i].className = tablinks[i].className.replace(" active", "");
        }
        document.getElementById(tabName).style.display = "block";
        evt.currentTarget.className += " active";
    }
    document.getElementById("defaultOpen").click();
    </script>

    <div class="tab">
      <button class="tablinks" onclick="openTab(event, 'q1')" id="defaultOpen">1</button>
      <button class="tablinks" onclick="openTab(event, 'q2')">2</button>
      <button class="tablinks" onclick="openTab(event, 'q3')">3</button>
    </div>            

    <?php if (!empty($_SESSION['msg'])) { ?>
        <div class="alert alert-info"><?php echo $_SESSION['msg']; ?></div>
    <?php } ?>

            <?php if (mysqli_num_rows($result) > 0): ?>
            <?php $index = 1; ?>
                <?php foreach ($result as $results):?>
    <div id="q<?php echo ($index++); ?>" class="tabcontent">
        <table class="table table-hover">
        <tbody>
                    <tr class="form-group">   
                        <h3 name="ques[<?php echo $test_id;?>]" style="text-indent: 40px;"> <?php echo $results['question']; ?> </h3>
                    </tr>
                    <tr class="form-group">
                        <label class="radio-inline" style="text-indent: 70px; font-size: 18px;">
                            &nbsp;&nbsp;<input style="font-size: 18px;" type="radio" name="ans[<?php echo $results['test_id'];?>" value="<?php echo $results['optiona'];?>"><?php echo $results['optiona'];?> 
                        </label>
                        <br>
                        <label class="radio-inline" style="text-indent: 70px; font-size: 18px;">
                             &nbsp;&nbsp;<input style="font-size: 18px;" type="radio" name="ans[<?php echo $results['test_id'];?>" value="<?php echo $results['optionb'];?>"><?php echo $results['optionb'];?> 
                        </label>
                        <br>
                        <label class="radio-inline" style="text-indent: 70px; font-size: 18px;">
                             &nbsp;&nbsp;<input style="font-size: 18px;" type="radio" name="ans[<?php echo $results['test_id'];?>" value="<?php echo $results['optionc'];?>"><?php echo $results['optiond'];?> 
                        </label>
                        <br>
                        <label class="radio-inline" style="text-indent: 70px; font-size: 18px;">
                             &nbsp;&nbsp;<input style="font-size: 18px;" type="radio" ame="ans[<?php echo $results['test_id'];?>" value="<?php echo $results['optiond'];?>"><?php echo $results['optiond'];?>
                        </label>
                        <br>
                    </tr>
        </tbody>
        </table>
    </div>
                <?php endforeach ?>
            <?php endif ?>