PHP update query not working - php

Question

As a task my teacher has given me (highschool year 10) to create a login form using html and php as we have just started to learn PHP i have made progress and this is my first attempt. I will go into more secure options later.
<?PHP
//Create the connection…
//("where the database is", 'Database login' , 'database password' , "Database name")
$con=mysqli_connect("", 'root', 'root', "Social");
//Check our connection…
if (mysqli_connect_errno($con))
{
echo " Sorry Mate";
}
$username = $_POST[username];
$password = $_POST[pawd];
$result = mysqli_query($con, "SELECT * FROM User_info");
$row = mysqli_fetch_array($result);
$value = $row['username'];
if($value == "$username")
{
$result = mysqli_query($con, "SELECT * FROM User_info");
$row = mysqli_fetch_array($result);
$value = $row['password'];
if($value == "$password")
{
$sql=("UPDATE user_check SET user = '1' ");
$sql=("UPDATE user_check SET name = '$username' ");
header( 'Location: feed.php' ) ;
}
else
{
header( 'Location: social.php' ) ;
}
}
else
{
header( 'Location: social.php' ) ;
}
if (!mysqli_query($con,$sql))
{
die('Error: ' . mysqli_error($con));
}
mysqli_close($con);
?>
Where it says
$sql=("UPDATE user_check SET user = '1' ");
$sql=("UPDATE user_check SET name = '$username' ");
The first one will work and update the database to 1 however the second one doesn't i have checked the name of the column changed the name of the variable $sql and $username and it still won't work is there any suggestions? Thankyou in advance :D

Answer 1

You first compare $_POST['username'] to the username column from the result, but then you try to update the name column in the database. My guess is that:
$sql = ("UPDATE user_check SET name = '$username' ");
should be:
$sql = ("UPDATE user_check SET username = '$username' ");

Answer 2

This looks strange:
$sql=("UPDATE user_check SET user = '1' ");
$sql=("UPDATE user_check SET name = '$username' ");
The second line will overwrite the value stored in the previous first one.
Try putting a
die($sql)
before the line where you call the SQL, to see if what you think you are running is what you are running.