PHP如果mysql查询显示产品是£0.00回声它是免费的

I am building a catalog function into my website to show listed products. In the database, I am storing how much the product costs as a decimal ie 0.00 / 2.50 / 5.00 etc. however, if the value is 0.00 I want it to echo to the user that the product is Free rather than 0.00. however what I have implemented isnt working, any advice?

if(!$start)
        $start=0; 
        $getquery = mysqli_query($conn, "SELECT ApplicationID, ApplicationName, ApplicationDescription, App_cost FROM apps WHERE ApplicationName LIKE '%$search%' OR ApplicationDescription LIKE '%$search%' LIMIT $start, $per_page;");
        if($row->App_cost="0.00")
        { $row->App_cost="Free";}

    while($row = $getquery->fetch_object()){
        $_GET['search']=$_POST['search'];
        echo "<div class=\"col-6 col-sm-6 col-lg-4\">";
        echo '<form method="post" action="cart_update.php">';
        echo '<h2>'.$row->ApplicationName.'</h2>';
        echo '<p>'.$row->App_cost.'</p>';
        echo '<button class="add_to_cart">Add To Cart</button>';
        echo '<input type="hidden" name="product_code" value="'.$row->ApplicationID.'" />';
        echo '<input type="hidden" name="type" value="add" />';
        echo '<input type="hidden" name="return_url" value="'.$current_url.'" />';
        echo '</form></div>';
        }  

try this

if(!$start)
            $start=0; 
            $getquery = mysqli_query($conn, "SELECT ApplicationID, ApplicationName, ApplicationDescription, App_cost FROM apps WHERE ApplicationName LIKE '%$search%' OR ApplicationDescription LIKE '%$search%' LIMIT $start, $per_page;");


        while($row = $getquery->fetch_object()){
            $_GET['search']=$_POST['search'];
            echo "<div class=\"col-6 col-sm-6 col-lg-4\">";
            echo '<form method="post" action="cart_update.php">';
            echo '<h2>'.$row->ApplicationName.'</h2>';
            if($row->App_cost=="0.00")
            { 
              echo '<p>Free</p>';
            }else{
               echo '<p>'.$row->App_cost.'</p>';
            }


            echo '<button class="add_to_cart">Add To Cart</button>';
            echo '<input type="hidden" name="product_code" value="'.$row->ApplicationID.'" />';
            echo '<input type="hidden" name="type" value="add" />';
            echo '<input type="hidden" name="return_url" value="'.$current_url.'" />';
            echo '</form></div>';
            } 

YOu placed your code wrong:

if(!$start)
        $start=0; 
        $getquery = mysqli_query($conn, "SELECT ApplicationID, ApplicationName, ApplicationDescription, App_cost FROM apps WHERE ApplicationName LIKE '%$search%' OR ApplicationDescription LIKE '%$search%' LIMIT $start, $per_page;");


    while($row = $getquery->fetch_object()){

        if($row->App_cost="0.00")
        { $row->App_cost="Free";}

        $_GET['search']=$_POST['search'];
        echo "<div class=\"col-6 col-sm-6 col-lg-4\">";
        echo '<form method="post" action="cart_update.php">';
        echo '<h2>'.$row->ApplicationName.'</h2>';
        echo '<p>'.$row->App_cost.'</p>';
        echo '<button class="add_to_cart">Add To Cart</button>';
        echo '<input type="hidden" name="product_code" value="'.$row->ApplicationID.'" />';
        echo '<input type="hidden" name="type" value="add" />';
        echo '<input type="hidden" name="return_url" value="'.$current_url.'" />';
        echo '</form></div>';
        } 

Or you can use this one line method:

            $row->App_const = ($row->App_const == '0.00' ? 'Free' : $row->App_const);
            echo '<p>' . $row->App_const . '</p>';