Need to update one row in database - php

Question

I am making an application and need to update only one row in my database. The way I build the application it updates all my rows in the database. Could someone look in my script and tell me how i can update one row?
I know i need to do something with id's but i dont know how..
Here is the script for the page where users can change the data from the database. In this way every record will update.
<section>
<?php
$sql = "SELECT naam, plaats.plaats, type.type, status FROM devices, type, plaats, status
WHERE devices.type_id = type.type_id
AND plaats.plaats_id = devices.plaats_id
AND status.status_id = devices.status_id
AND plaats.plaats ='benedenverdieping'";
$result = $con->query($sql);
if ($result->num_rows > 0) {
echo '<table><tr><td>Naam</td><td>Plaats</td><td>Type</td><td>Status</td><td>open/dicht</td><td>Submit</td></tr>';
while($row = $result->fetch_assoc()) {
echo '<tr>';
echo '<td>' .$row['naam']. '</td>';
echo '<td>' .$row['plaats']. '</td>';
echo '<td>' .$row['type']. '</td>';
echo '<td>' .$row['status']. '</td>';
echo '<td>';?>
<form action="opendicht.php" method="post">
<select name="opendicht">
<option name="open" value="1">open</option>
<option name="dicht" value="2">dicht</option>
</select>
<?php '</td>';
echo '<td>'?>
<input type="submit" value="Doorvoeren" name="submit">
</form>
<?php '</td>';
}
echo '</table>';
}
?>
</section>
Here is the script which execute the users input. Because of the sql query's it wont work for only one record. The way it works right now is the query updates every record with status_id 1 or 2. In the database the 1 stands for open and the 2 stands for closed. I can't find a way to let the query update only one row of data.
<?php
session_start();
$naam = $_SESSION['username'];
echo $naam;
include '../dbconnect.php';
date_default_timezone_set("Europe/Amsterdam");
$t=time();
$aanpassing = date("d-m-y h:i",$t);
$sel_device_id = ("SELECT device_id FROM devices");
$run_device_id = mysqli_query($con, $sel_device_id);
if(isset($_POST['submit']))
{ // Fetching variables of the form which travels in URL
$opendicht = $_POST['opendicht'];
if($opendicht =='1')
{
//UPDATE devices SET status_id = $opendicht, username = (SELECT user_id FROM users WHERE username = '$naam'), timestamp = '$timestamp' WHERE status_id = '2'
mysqli_query($con,"UPDATE devices SET status_id = $opendicht, username = '$naam', tijd = '$aanpassing' WHERE status_id = 2");
}
else
{
mysqli_query($con,"UPDATE devices SET status_id = $opendicht, username = '$naam', tijd = '$aanpassing' WHERE status_id = 1");
}
}
else{
echo "er is iets fout gegaan";
}
mysqli_close($con); // Closing Connection with Server
header( "refresh:0;url=index.php" );
?>

Answer 1

These are your UPDATE queries:
mysqli_query($con,"UPDATE devices SET status_id = $opendicht, username = '$naam', tijd = '$aanpassing' WHERE status_id = 1");
mysqli_query($con,"UPDATE devices SET status_id = $opendicht, username = '$naam', tijd = '$aanpassing' WHERE status_id = 2");
You're updating all the rows where the status_id is 1 or 2.
You need to add an AND condition to identify the unique row identifier to update.