datetime edit php to mysql error - php

Question

I already connected my sql to database, but my isset post does not work
<div class="container" style="margin-top:60px;margin-bottom:60px;">
<div class="form-group pull-right">
</div>
<div class="row">
<p> Set Start DateTime<p>
<input type="datetime-local" name="start"><br><br>
<button type="submit" class="btn btn-primary" name="submit1">SUBMIT</button>
<br><br>
<p> Set Deadline<p>
<input type="datetime-local" name="end"><br><br>
<button type="submit" class="btn btn-primary" name="submit2">SUBMIT</button>
<br><br>
</div>
</div>
<?php
if(isset($_POST['submit1'])){
$name = $_POST['start'];
$sql = "UPDATE tbdeadline SET
start = '$name'
WHERE id = '1'
";
if ($this->con->query($sql) === TRUE){
echo '<script>window.location.href="deadline.php"</script>';
}
else{
echo 'error';
}
}
?>
I want to update datetime in my "user" database whose table name is "start" and id = "1"
But my html is getting nowhere. It is not showing any error or anything else.
What am I doing wrong, how can I fix this?

Answer 1

I think value from is not send via $_POST. If I want to check if form is send I use
<input type="hidden" name="submit1" value="1" />
And check via
if (isset($_POST['submit1'])
Try it.

Answer 2

The sql code is vulnerable to SQL injection - or it would be if it were not within single quotes rather than double. Using single quotes means that any PHP variable within must be escaped - easier to use double quotes and the values of the variables will be OK.
<p> Set Start DateTime<p>
<input type='datetime-local' name='start'><br><br>
<button type='submit' class='btn btn-primary'>SUBMIT</button>
<br><br>
<p> Set Deadline<p>
<input type='datetime-local' name='end'><br><br>
<button type='submit' class='btn btn-primary'>SUBMIT</button>
<br><br>
</div>
</div>
<?php
if( isset( $_POST['start'],$_POST['end'] )){
$name = $_POST['start'];
$end = $_POST['end'];
/* This is vulnerable to SQL injection !! */
/* use double quotes around sql or better mysqli/PDO and `prepared statements` */
$sql = "UPDATE tbdeadline SET start = '$name' WHERE id = '1'";
if( $this->con->query($sql) === TRUE ){
echo '<script>window.location.href='deadline.php'</script>';
} else{
echo 'error';
}
}
?>

Answer 3

You forgot to add the values for your Submit buttons.
You need to update your Submit buttons like below:
<button type="submit" class="btn btn-primary" name="submit1" value="start">SUBMIT</button>
<button type="submit" class="btn btn-primary" name="submit2" value="end">SUBMIT</button>
Also make sure your form method must be POST like below:
<form method="post">
If you still get isset error then you need to debug your $_POST to check whether form data is coming via form or not. Add below code before if condition to test:
print_r($_POST); die;
And use MySqli Prepared Statements for updating your query to make it more Secure.
Follow below link to learn more:
http://php.net/manual/en/mysqli.quickstart.prepared-statements.php