点击链接时丢失列表

Question

I am going through a tutorial and I have a sidebar with 2 sections: category and brands. When I click any item within the brands list everything works fine but when I click any item within the category list, the brands just disappear from the page, can anyone help, please?

I am using the following code:

"<li><a href='index.php?brand=$brand_id'>$brand_title</a></li>";

This works fine, but when when I use this:

"<li><a href='index.php?cat=$cat_id'>$cat_title</a></li>";

That's where I loose the brands list.

Answer 1

From the Code out of the comment you should try this,

<?php
    echo "<li><a href='index.php?brand=" . $brand_id . "'>" . $brand_title . "</a></li>";
    echo "<li><a href='index.php?cat=" . $cat_id . "'>" . $cat_title . "</a></li>";
?>

EDIT:

function getBrands(){ 
    if(!isset($_GET['cat'])){ 
        global $connect; 
        $get_brands = "select * from brands"; 
        $run_brands = mysqli_query($connect, $get_brands); 
        while ($row_brands=mysqli_fetch_array($run_brands)){ 
            $brand_id = $row_brands['brand_id']; 
            $brand_title = $row_brands['brand_title']; 
            echo "<li><a href='index.php?brand=" . $brand_id . "'>" . $brand_title . "</a></li>"; 
        }
    }
}

So if you get a categorie the getBrands function do nothing. remove the if statement.

function getBrands(){ 
       global $connect; 
       $get_brands = "select * from brands"; 
       $run_brands = mysqli_query($connect, $get_brands); 
       while ($row_brands=mysqli_fetch_array($run_brands)){ 
            $brand_id = $row_brands['brand_id']; 
            $brand_title = $row_brands['brand_title']; 
            echo "<li><a href='index.php?brand=" . $brand_id . "'>" . $brand_title . "</a></li>"; 
        }
    }