Adding filters to dynamic search engine php

i'm working on adding filters to my database but i have no knowledge and google didnt really help so i appreciate all the advice =)

I would like to add filters like name and price and arrange by asc and desc order.

my db has 4 columns, id(int15) , brand/model(varchar50), picture(longblob), price (varchar50).

Any advice on how to approach this(best if have some examples as i'm a beginner)? Currently below i created the form asc and desc below but i have no idea on how to integrating to my php code. I've set the form name as "results"

What i currently have is index.php

<form action="search.php" type="text"  method="POST">
Name: <input type ="text" name="search_name" size='30' /> 
<input type="submit" value="Search">
<br><br>
<b>Arrange Price by :</b>

<select name="results">
<option value="">Select...</option>
<option value="asc">Ascending</option>
<option value="desc">Descending</option>
</select>

<?php

if (isset($_POST['search_name'])) {
        $search_name = $_POST['search_name'];

        if (!empty($search_name)){

            if (strlen($search_name)>=3) {

            $query = "SELECT * FROM `shoes` WHERE `brand/model` LIKE '".mysql_real_escape_string($search_name)."%' ORDER BY `price` ASC";
            $query_run = mysql_query($query);
            $query_num_rows = mysql_num_rows($query_run);

            if ($query_num_rows>=1) {
                echo $query_num_rows.' Results found:<br>';

                while ($query_row = mysql_fetch_array($query_run)) {


                        $picture = $query_row['picture'];
                        echo "</br>";
                        echo $query_row ['brand/model']; 
                        echo str_repeat('&nbsp;', 15); // adds 5 spaces
                        echo $query_row ['price'];
                        echo "</br>";
                        echo "</br>";
                        //header("content-type: image/jpeg");
                        echo "<img src='image.php?id=".$query_row['id']."' width='300' height='200' />";
                        echo "</br>";



                }
            } else {
                echo 'No Results Found.';
            }
        } else {
            echo 'Text field must be more than 3 characters.';
        }

    } else {
        echo 'Text Field Cannot be Empty!';
    }
}

Solution

Try using this code,

Changes what I have done are, created anchor's of your field name as table header
by default the headers are in ASC order, if we click it, it changes to DESC order
the sql query then uses the field name in GET to order the records
the search term is also then saved in the GET request so that we can persist it ahead
as search term is sometimes received in GET and sometimes in POST, have used REQUEST here, to get data

    if (!empty($search_name)){

        if (strlen($search_name)>=3) {

            if(empty($_REQUEST['searchTrm']))
                $_REQUEST['searchTrm'] = 'price';

            if(empty($_REQUEST['order']))
                $_REQUEST['order'] = 'ASC';

            $query = "SELECT * FROM `shoes` WHERE `brand/model` LIKE '".mysql_real_escape_string($search_name)."%' ORDER BY ".$_REQUEST['searchTrm']." ".$_REQUEST['order'];

            $query_run = mysql_query($query);
            $query_num_rows = mysql_num_rows($query_run);

        if ($query_num_rows>=1) {
            echo $query_num_rows.' Results found:<br>';
?>
        <table border=1>
            <tr>
                <td>
                    <?php
//use your sql field name as searchTrm value
if($_REQUEST['searchTrm'] == 'brand/model' && $_REQUEST['order'] == 'DESC') { ?>
                        <a href='?searchTrm=brand/model&order=ASC&search_name=<?php echo $_REQUEST['search_name']?>' title = 'ASC'>Brand Name</a>
                    <?php } else { ?>
                        <a href='?searchTrm=brand/model&order=DESC&search_name=<?php echo $_REQUEST['search_name']?>' title = 'DESC'>Brand Name</a>
                    <?php } ?>
                </td>
                <td>
                    <?php if($_REQUEST['searchTrm'] == 'price' && $_REQUEST['order'] == 'DESC') { ?>
                        <a href='?searchTrm=price&order=ASC&search_name=<?php echo $_REQUEST['search_name']?>' title = 'ASC'>Price</a>
                    <?php } else { ?>
                        <a href='?searchTrm=price&order=DESC&search_name=<?php echo $_REQUEST['search_name']?>' title = 'DESC'>Price</a>
                    <?php } ?>
                </td>
                <td>Image</td>
            </tr>
            <?php
            while ($query_row = mysql_fetch_array($query_run)) {
                 $picture = $query_row['picture'];
                ?>
                <tr>
                    <td><?php echo $query_row['brand/model'];?></td>
                    <td><?php echo $query_row['price'];?></td>
                    <td><img src='image.php?id=<?php echo $query_row['id'];?>' width='300' height='200' /></td>
                </tr>
                <?php
            }
        ?> </table> <?php
        } else {
            echo 'No Results Found.';
        }
    } else {
        echo 'Text field must be more than 3 characters.';
    }

} else {
    echo 'Text Field Cannot be Empty!';
}
}