Php 引导网格不'；我不能正常工作

我目前正在自己做一个项目，到目前为止一切都很顺利，但在修改了一点代码后，我的网格看起来不像我想要的那样。你可以看到应该有3列，而不是只有一列，我不明白为什么会发生这种情况

提前谢谢

 <div class="col-sm-4">
 <h4 class="card-title">Misiuni Active</h4>
 <div class="row">
                <?php
                $today = date("Y-m-d");
                $result = mysqli_query($conn,"SELECT * FROM misiuni");

                if(mysqli_num_rows($result)){

                while ($row = mysqli_fetch_assoc($result)) {

                    if ($today < $row['deadline']) {
                        echo '<form method="POST" action="accept.php">';
                        echo '<div class="ribbon-wrapper card">';
                        echo '<input type="hidden" name="titlu" value="' . $row['titlu'] . '"></input>';
                        echo '<div class="ribbon ribbon-default">' . $row['titlu'] . '</div>';
                        echo '<p class="ribbon-content">' . $row['misiune'] . '</p>';
                        echo '<center><br><h4 class="card-title">Reward:</h4></center>';
                        echo '<center><img src=' . $row['reward'] . ' width="200px" height="200px"></center>';

                        $sql = mysqli_query($conn,"SELECT * FROM misiuni_acceptate where username='". $_SESSION['username'] . "' AND titlu_misiune='". $row['titlu'] . "'");

                        if(mysqli_num_rows($sql)){

                            while ($row = mysqli_fetch_assoc($sql)) {

                                if($row['status']=='yes'){

                                    echo '<input type="submit" class="btn btn-info" value="Misiune finalizată" disabled>';

                                }else {

                                    echo '<input type="submit" class="btn btn-warning" value="Misiune în curs" disabled>';

                                }
                            }
                        }else {

                            echo '<input type="submit" class="btn btn-success" value="Acceptă misiunea">';

                        }

                        echo '</div>';
                        echo '</div>';
                        echo '</form>';


                    }
                }
            }

?>

              </div>
     </div>

米苏尼活性

米苏尼活性
乍一看，我没有看到
标记，很难跟踪不同的标记以查看哪个匹配。你改变了什么“破坏”了你的项目？kchason抢先告诉我，记住如果你的浏览器不够大，它会把div“堆积”成一列。如果你把你的浏览器拉得更大，它会返回到3列吗？我添加了带有第二个查询和分开的提交按钮的部分。不，如果我拉伸浏览器就不会。等等，你的编辑会改变整个事情！首先从col-sm-4开始，您只能在其中放置一行。您必须这样做：声明一行，然后在该行中声明col-sm-4。您确实需要查看引导文档并查看示例代码，您的代码到处都是：-）您的代码容易受到攻击。您应该通过或驱动程序将准备好的语句与绑定参数一起使用。有一些很好的例子。现在你可以用css设置一个空白底部为Misiuni Active，它可以工作了
<div class="row">
<h4 class="card-title">Misiuni Active</h4>

<?php
                $today = date("Y-m-d");
                $result = mysqli_query($conn,"SELECT * FROM misiuni");

                if(mysqli_num_rows($result)){

                while ($row = mysqli_fetch_assoc($result)) {

                    if ($today < $row['deadline']) {
                        echo '<div class="col-xs-6 col-sm-3">'
                        echo '<form method="POST" action="accept.php">';
                        echo '<div class="ribbon-wrapper card">';
                        echo '<input type="hidden" name="titlu" value="' . $row['titlu'] . '"></input>';
                        echo '<div class="ribbon ribbon-default">' . $row['titlu'] . '</div>';
                        echo '<p class="ribbon-content">' . $row['misiune'] . '</p>';
                        echo '<center><br><h4 class="card-title">Reward:</h4></center>';
                        echo '<center><img src=' . $row['reward'] . ' width="200px" height="200px"></center>';

                        $sql = mysqli_query($conn,"SELECT * FROM misiuni_acceptate where username='". $_SESSION['username'] . "' AND titlu_misiune='". $row['titlu'] . "'");

                        if(mysqli_num_rows($sql)){

                            while ($row = mysqli_fetch_assoc($sql)) {

                                if($row['status']=='yes'){

                                    echo '<input type="submit" class="btn btn-info" value="Misiune finalizată" disabled>';

                                }else {

                                    echo '<input type="submit" class="btn btn-warning" value="Misiune în curs" disabled>';

                                }
                            }
                        }else {

                            echo '<input type="submit" class="btn btn-success" value="Acceptă misiunea">';

                        }

                        echo '</div>';
                        echo '</div>';
                        echo '</form>';
                        echo '</div>';


                    }
                }
            }

?>