how to use old profile picture if no image selected in php - php

Question

this is my code updating data. How is it possible to use old image if no image is selected?
its a profile page when someone updates his profile but don't select the image for update then old image should be remained there..
<?php
if(isset($_POST['update_user'])){
//getting text data from field
$update_id = $user_id;
$fullname = $_POST['fullname'];
$designation = $_POST['designation'];
$username = $_POST['username'];
$location="images/users/";
$name=$_FILES['user_img']['name'];
$temp_name=$_FILES['user_img']['tmp_name'];
if(isset($name)){
move_uploaded_file($temp_name,$location.$name);
}
else
{
echo $user_img;
}
$update_product = "update user set FullName='$fullname',Designation='$designation',UserName='$username',User_Pic='$name' where Id='$update_id'";
$run_product = mysqli_query($con, $update_product);
if ($run_product){
echo"<scripy>alert('Update Successful')</script>";
echo "<script>window.open('user_manage.php','_self') </script>";
}
}
?>

Answer 1

First, you need to fetch the existing user details from the database and check if the user already has a profile picture.
Next, if the user has uploaded a new image, then you can delete the old profile picture using unlink() function. If the user has not uploaded a new picture, you can retain the old picture.
See the code below.
<?php
if(isset($_POST['update_user'])){
//getting text data from field
$update_id = $user_id;
$fullname = $_POST['fullname'];
$designation = $_POST['designation'];
$username = $_POST['username'];
$location="images/users/";
//Fetch user details
$query = "SELECT User_Pic FROM user WHERE Id=" . $update_id;
$result = mysqli_query($con, $query);
$row = false;
if (mysqli_num_rows($result) > 0) {
$row = mysqli_fetch_assoc($result);
}
if (isset($_FILES['user_img'])) { //User uploaded new image
if ($row) {
unlink($location . $row['User_Pic']); //Delete old pic
}
$name=$_FILES['user_img']['name'];
$temp_name=$_FILES['user_img']['tmp_name'];
move_uploaded_file($temp_name,$location.$name);
$update_product = "update user set FullName='$fullname',Designation='$designation',UserName='$username',User_Pic='$name' where Id='$update_id'";
} else { //User did not upload image
if ($row) {
echo $location . $row['User_Pic']; //Echo current image path
}
$update_product = "update user set FullName='$fullname',Designation='$designation',UserName='$username' where Id='$update_id'";
}
$run_product = mysqli_query($con, $update_product);
if ($run_product){
echo"<scripy>alert('Update Successful')</script>";
echo "<script>window.open('user_manage.php','_self') </script>";
}
}
?>
Please note that the code shown here does not change the filename when storing the files on the server. This will cause problems when two person upload pictures with same filename. You need to implement an appropriate solution for that.