Display different row of a database upon clicking a button - php

Question

I have a database of mosques with the following fields: mosque_id, mosque_name, prefecture, address, postal_code, website, email1, phone1 . What I want to do is to display the information of the first mosque (mosque_id=1) in a form and when I click "Next", the information of the second mosque (mosque_id=2) will be displayed.
So far, I've been able to use mosque_id to select an entire row and display the information, but I've been struggling to find a way to switch to the next one. I'm very new to PHP and MYSQL, any help would be appreciated.
<?
$mosque_id = 1;
$result = mysql_query("SELECT * FROM Mosque WHERE mosque_id='$mosque_id'");
$row = mysql_fetch_assoc($result);
?>
<form action="insert.php" method="post">
Mosque Name: <?php print('<input type="text" name="firstname" value="' . $row['mosque_name'] . '"/><br>')?>
Prefecture: <?php print('<input type="text" name="firstname" value="' . $row['prefecture'] . '"/><br>')?>
Address: <?php print('<input type="text" value="' . $row['address'] . '"/><br>')?>
Postal Code: <?php print('<input type="text" value="' . $row['postal_code'] . '"/><br>')?>
Website: <?php print('<input type="text" value="' . $row['website'] . '"/><br>')?>
Email 1: <?php print('<input type="text" value="' . $row['email1'] . '"/><br>')?>
Contact number 1: <?php print('<input type="text" value="' . $row['phone1'] . '"/><br>')?>
<input type="button" value="Next Mosque" onclick=""/>
</form>

Answer 1

<?php
$mosque_id = (isset($_GET['mosque_id']) ? intval($_GET['mosque_id']) : 1); // suppose you know that '1' is the first id in your table
$result = mysql_query("SELECT * FROM Mosque WHERE mosque_id>='$mosque_id' limit 2");
$row = mysql_fetch_assoc($result); // this is the row you're gonna display in the form
$row2 = mysql_fetch_assoc($result); // this will tell us about the next row
?>
<form action="insert.php" method="post">
Mosque Name: <?php print('<input type="text" name="firstname" value="' . $row['mosque_name'] . '"/><br>')?>
Prefecture: <?php print('<input type="text" name="firstname" value="' . $row['prefecture'] . '"/><br>')?>
Address: <?php print('<input type="text" value="' . $row['address'] . '"/><br>')?>
Postal Code: <?php print('<input type="text" value="' . $row['postal_code'] . '"/><br>')?>
Website: <?php print('<input type="text" value="' . $row['website'] . '"/><br>')?>
Email 1: <?php print('<input type="text" value="' . $row['email1'] . '"/><br>')?>
Contact number 1: <?php print('<input type="text" value="' . $row['phone1'] . '"/><br>')?>
<input type="button" value="Next Mosque" onclick="window.location = 'path-to-your-page?mosque_id=<?php echo $row2['mosque_id'];"/>
</form>

Answer 2

First: please use mysqli functions or PDO class, not mysql functions, they are deprecated.
Secondly: use long PHP tags
But You are on right track:
Replace Your first row with:
$mosque_id = (isset($_GET['mosque_id']) ? intval($_GET['mosque_id']) : 1);
And in the end
<input type="button" value="Next Mosque" onclick="javascript: document.location = '?mosque_id=<?php echo ($mosque_id + 1);?>"/>
You also need to write some checks after query, if such id exists and actually, if you develop further, you need to check for next mosque_id also, because if you delete some rows, id-s may not be in correct order like 1, 2, 3, 4 but 1, 3, 7, 9
(hint: for next id use WHERE mosque_id > current_id ORDER BY mosque_id DESC LIMIT 1 in MySQL)

Answer 3

Just have a hidden input holding the ID, and increment it when the page loads. Then, when you submit, the ID will be submitted too.
<?
if (isset($_POST['id']) {
$id = $_POST['id'];
}
else {
$id = 1;
}
$result = mysql_query("SELECT * FROM Mosque WHERE mosque_id='$id'");
...
?>
<form action="insert.php" method="post">
...
<input type='hidden' name='id' value='<?php echo $mosque_id++; ?> />
<input value="Next Mosque" />
</form>
And by the way, use PDO. It's very easy to learn and adds a huge level of security to your application.