Mysql query array - php

Question

I have two tables:
1 - hotels[id,name,extras] ( name of hotels with column extras which I've select for each one)
2 - extras[id,name] ( here's the extras of hotel like wifi,tv,swim... )
$name = $_GET['name'];
$hotels_q = mysql_query("SELECT * FROM `hotels` WHERE `name`='$name'") or die (mysql_error());
$hotels_row = mysql_fetch_array($hotels_q);
$id = $hotels_row['id'];
$extras = explode(",", $hotels_row['extras']);
$ekstras_q = mysql_query("SELECT * FROM `extras` order by id") or die(mysql_error());
While($ekstras_row = mysql_fetch_array($ekstri_q)){
$eid = $ekstras_row['id'];
$ename = $ekstri_row ['name'];
echo '<ul><li><input type="checkbox" name="extras['.$eid.'][]" value="'.$ename.'"';
if (in_array($eid, $ekstras)) echo'checked';
echo'/>'.$ename.'</li></ul>';
Problem is here extras_q displays all entries with checked ones from table, but I want only to display only checked items!

Answer 1

Since you're storing your extra IDs in one column as a comma separated string, I think you should be able to do this by not exploding that value, and then using the CSV string as an IN criteria in your second query.
//...
$extras = $hotels_row['extras']; // don't explode
// Use IN with the $extras CSV here
$ekstras_q = mysql_query("SELECT * FROM `extras`
WHERE id IN ($extras) ORDER BY id") or die(mysql_error());
If you are able to modify your database, you can instead create a many-to-many relationship between hotels and extras by adding a table to join those two items together instead of using a CSV column as you currently are. This can make it easier to write queries to select the related records.
If you add a third table hotel_extras with columns hotel_id and extra_id, you can insert one row for each extra that each hotel has. For example, if the hotel with id 1 has several different extras, its entries in that table would look like this:
table: hotel_extras
_______________________
| hotel_id | extra_id |
=======================
| 1 | 1 |
| 1 | 3 |
| 1 | 4 |
-----------------------
Here is an example using PDO of how you could query data from a setup like that:
$sql = "SELECT e.id, e.name
FROM hotels h
INNER JOIN hotel_extras he ON h.id = he.hotel_id
INNER JOIN extras e ON he.extra_id = e.id
WHERE h.`name` = ?";
$stmt = $pdo->prepare($sql);
$stmt->bindValue(1, $_GET['name']);
$stmt->execute();
while ($row = $stmt->fetch(PDO::FETCH_ASSOC)) {
$eid = $row['id'];
$ename = $row['name'];
'<li><input type="checkbox" name="extras['.$eid.'][]" value="'.$ename.'" checked/>'.$ename.'</li>';
}