栏目列表

catlist.php

// 注意：cat下的大多数操作是根据cat_id来完成的
$conn = mysql_connect('localhost', 'root', '');
mysql_query('use blog', $conn);
mysql_query('set names utf8');

$sql = "select * from cat";
$rs = mysql_query($sql);
$cat = array();

while( $row = mysql_fetch_assoc($rs) ) {
    $cat[] = $row;
}
// print_r($cat);// 二维数组

require('./view/admin/catlist.html');

catlist.html

<?php foreach($cat as $key => $value) { ?>
<tr>
    <td><?php echo $value["cat_id"] ?></td>
    <td><?php echo $value["catname"] ?></td>
    <td><span class="badge"><?php echo $value["num"] ?></span></td>
    <td>
        <a href="catdel.php?cat_id=<?php echo $value["cat_id"]; ?>">删除</a>|
        <a href="catedit.php?cat_id=<?php echo $value["cat_id"]; ?>">编辑</a>
    </td>
</tr>
<?php } ?>

catdel.php

// 通过cat_id去删除
<?php 

    $cat_id = $_GET['cat_id'];
    
    $conn = mysql_connect('localhost', 'root', '');
    mysql_query('use blog', $conn);
    mysql_query('set names utf8');

    // 检测栏目ID是否为数字
    if( !is_numeric($cat_id) ) {// 数字字符串也行喔
        echo "栏目不合法";
        exit();
    }

    // 检测栏目是否存在
    $sql = "select count(*) from cat where cat_id = $cat_id";
    $rs = mysql_query($sql);
    if( mysql_fetch_row($rs)[0] == 0 ) {
        echo "栏目不存在";    
        exit();
    }
    
    // 检测栏目下是否有文章
    $sql = "select count(*) from art where cat_id=$cat_id";
    $rs = mysql_query($sql);
    if( mysql_fetch_row($rs)[0] != 0 ) {// 当前栏目下有文章
        echo "栏目下有文章不能删除";
        exit();
    }

    // 检测完毕，删除
    $sql = "delete from cat where cat_id=$cat_id";
    if( mysql_query($sql) ) {// 删除返回的是true or false
        echo "栏目删除成功";
    }
    else {
        echo "栏目删除失败";
    }
 ?>

catedit.php

<meta charset="utf8">
<?php 

    $cat_id = $_GET['cat_id'];
    $conn = mysql_connect('localhost', 'root', '');
    mysql_query('use blog', $conn);
    mysql_query('set names utf8');

    // 先检查
    // 检测栏目ID是否为数字
    if( !is_numeric($cat_id) ) {// 数字字符串也行喔
        echo "栏目不合法";
        exit();
    }
    // 检测栏目是否存在
    $sql = "select count(*) from cat where cat_id = $cat_id";
    $rs = mysql_query($sql);
    if( mysql_fetch_row($rs)[0] == 0 ) {
        echo "栏目不存在";    
        exit();
    }

    if( empty($_POST) ) {// 没有点提交呢
        $sql = "select catname from cat where cat_id=$cat_id";// 根据cat_id找cat_name
        $rs = mysql_query($sql);
        $cat = mysql_fetch_assoc($rs);// 视图中输出$cat['catname']
        require('./view/admin/catedit.html');
    }
    else {// 有post点提交了
        $sql = "update cat set catname='$_POST[catname]' where cat_id=$cat_id";// 根据cat_id修改cat_name
        if( !mysql_query($sql) ) {
            echo "栏目修改失败";
        }
        else {
            echo "栏目修改成功";
        }
    }
    
 ?>