Question

我有一个PHP循环遍历我的Media表，在表中他们是这些字段： id（唯一id_，post_id（每个帖子的随机ID），user_id，file_format，group_id

如果上传了一组多个图像，则它们具有唯一的post_id，并具有相同的group_id，以区分其他组照片。但是，我无法弄清楚如何将循环内的这些组与if语句分开以打破div行。这是我的代码：

＆＃13;

<?php
		$sql = "SELECT * FROM media WHERE user_id = '".$_SESSION['user']."'";
		$result = $conn->query($sql);
		?>
		
		<?php while($row = mysqli_fetch_array($result)):?>
			<?php $group_id = $row['group_id'] ?>
		<?php if($row['group_id'] == $group_id):?>
			<div class="card-group" style="color:black;">
			  <div class="card">
			    <img class="card-img-top" src="uploads/<?=$row['post_id']?>.<?=$row['file_format']?>" alt="Card image cap">
			    <div class="card-body">
			      <h4 class="card-title">Card title</h4>
			      <p class="card-text">This is a wider card with supporting text below as a natural lead-in to additional content. This content is a little bit longer.</p>
			      <p class="card-text"><small class="text-muted">Last updated 3 mins ago</small></p>
			    </div>
			  </div>
			</div>
		<?php endif;?>
		<?php endwhile;?>

＆＃13;

Answer 1

我假设您的表media是这样的：

+---------+-------------+-----------+-----------+---------+
|unique_id| post_id     | user_id   |file_format|group_id |
+---------+-------------+-----------+-----------+---------+
|1        |56           | johndoe66 |.jpg       |Home     |
+---------+-------------+-----------+-----------+---------+
|2        |57           | johndoe66 |.png       |School   |  
+---------------------------------------------------------+

首先得到SELECT DISTINCT group_id FROM media WHERE user_id = $_SESSION['user_id']

$conn = new mysqli("server","user","pass","your_database_name");
//will use the Object Oriented way, i'm used to it
$sql = "SELECT DISTINCT group_id FROM media WHERE user_id = $_SESSION['user_id']`";

$groups_result = $conn->query($sql);
//create a group array and format it as you like
$user_groups = array();
while($row = $groups_result->fetch_array()){
   $user_groups[] = $row['group_id`];
}

首先会获得该用户的所有不同组，并将其存储在$user_groups中。然后：

Foreach $user_groups：

您现在想要获取每个组的帖子：

for($i = 0;$i < count($user_groups);$i++){
  $sql = "SELECT * FROM media WHERE user_id = '".$_SESSION['user_id']."' AND group_id = '".$user_groups[$i]."'"
  //create a group div with maybe the <div id='$user_groups[$i]'>
   while($row = $mysqli_fetch_array($conn->query($sql)){
      //create a picture collage of all the posts in the current $i group
   }
  //close the group </div>
}

编辑有帮助吗？。

Answer 2

你想要得到类似的东西吗？我使用临时变量来确定组在循环期间何时更改，并且我通过group_id命令您的mysql查询：

<?php
$sql = "SELECT * FROM media WHERE user_id = '".$_SESSION['user']."' order by group_id";
$result = $conn->query($sql);
$oldGroupId = -1;

while($row = mysqli_fetch_array($result)) {
    $group_id = $row['group_id'];
    if($oldGroupId != $group_id) {
        if($oldGroupId != -1) {
            echo("</div>");
        }
        echo("<div class=\"card-group\" style=\"color:black;\">\n");
        $oldGroupId = $group_id;
    }
    echo("<div class=\"card\">
            <img class=\"card-img-top\" src=\"uploads/<?=".($row['post_id'])."?>.<?=".($row['file_format'])."?>\" alt=\"Card image cap\">
            <div class=\"card-body\">
              <h4 class=\"card-title\">Card title</h4>
              <p class=\"card-text\">This is a wider card with supporting text below as a natural lead-in to additional content. This content is a little bit longer.</p>
              <p class=\"card-text\"><small class=\"text-muted\">Last updated 3 mins ago</small></p>
            </div>
          </div>");
}
echo("</div>\n");

PHP循环，单独的结果依赖于group_id

2 个答案: