在关闭标记外关闭while循环并在旁边使用Html时出现PHP错误 - PHP errors when closing while loop outside closing tag and using Html alongside

PHP errors when closing while loop outside closing tag and using Html alongside

我搜索过并偶然发现了许多这样的问题。但这并不能回答我的问题。因此，我在这里再次提出这个问题。这是我的php代码：

<?php
    include("connect.php");
    if(isset($_GET['view'])) {
        $query = "SELECT * FROM posts order by 1 DESC";
        $run = mysqli_query($con, $query);
        while(mysqli_fetch_array($run)) {
        $id = $row['Post_id'];
        $title = $row['Post_title'];
        $date = $row['Post_date'];
        $author = $row['Post_author'];
        $content = $row['Post_content'];
?>
    <table width="800" align="center" border="5">
            <tr>
                   <td align="center" colspan="9"><h1>View all Posts</h1></td>
            </tr>
                </table>
   <?php
        } 
   } 
   ?>

问题出在最后一行<?php } } ?>我下面的老师正是这样做的。他的代码运行得非常好。但我的错误是，"第27、28、29、30行的未定义变量行"。如有任何帮助，我们将不胜感激。

您需要在while循环中定义$row来迭代查询中的每个记录：

while($row = mysqli_fetch_array($run)) {
    // Do something
}

您应该定义$row变量。

<?php
    include("connect.php");
        if(isset($_GET['view'])) {
            $query = "SELECT * FROM posts order by 1 DESC";
            $run = mysqli_query($con, $query);
            while($row = mysqli_fetch_array($run)) {
            $id = $row['Post_id'];
            $title = $row['Post_title'];
            $date = $row['Post_date'];
            $author = $row['Post_author'];
            $content = $row['Post_content'];
        ?>
    <table width="800" align="center" border="5">
            <tr>
                   <td align="center" colspan="9"><h1>View all Posts</h1></td>
            </tr>
                </table>
                            <?php } } ?>

只需更改

 while($row = mysqli_fetch_array($run)) {
//Code
}

尝试这个

<?php
    include("connect.php");
    if(isset($_GET['view'])) {
        $query = "SELECT * FROM posts order by 1 DESC";
        $run = mysqli_query($con, $query);
        while($row =mysqli_fetch_array($run)) {
        $id = $row['Post_id'];
        $title = $row['Post_title'];
        $date = $row['Post_date'];
        $author = $row['Post_author'];
        $content = $row['Post_content'];
?>
    <table width="800" align="center" border="5">
            <tr>
                   <td align="center" colspan="9"><h1>View all Posts</h1></td>
            </tr>
                </table>
   <?php
        } 
   } 
   ?>

是。因为您没有定义数组$row。你必须定义$row=array（）；在使用之前。就像下面的

<?php
    include("connect.php");
        if(isset($_GET['view'])) {
            $query = "SELECT * FROM posts order by 1 DESC";
            $run = mysqli_query($con, $query);
             $row= array();
            while($row = mysqli_fetch_array($run)) {
            $id = $row['Post_id'];
            $title = $row['Post_title'];
            $date = $row['Post_date'];
            $author = $row['Post_author'];
            $content = $row['Post_content'];
        ?>
<table width="800" align="center" border="5">
            <tr>
                   <td align="center" colspan="9"><h1>View all Posts</h1></td>
            </tr>
                </table>
                            <?php } } ?>

这应该对你有用。

定义$row变量。

while($row=mysqli_fetch_array($run))