PHP update data to mysql (ERROR with undefined variable) - php

Question

This is the part of the code:
It first retrieves the information according to the id. but When i change one of the information and clicked update, it gives me undefined variable error and couldnt update at all.
<?php
include("includes/connect.php");
if(isset($_GET['edit'])) {
$edit_id = $_GET['edit'];
$edit_query = "select * from posts where post_id = '$edit_id' ";
$run_edit = mysqli_query($con,$edit_query);
while ($edit_row=mysqli_fetch_array($run_edit)) {
$post_id = $edit_row['post_id'];
$post_title = $edit_row['post_title'];
$post_author = $edit_row['post_author'];
$post_keywords = $edit_row['post_keywords'];
$post_image = $edit_row['post_image'];
$post_content = $edit_row['post_content'];
}
}
?>
<form method="post" action="edit.php?edit_form=<?php echo $post_id; ?>" enctype="multipart/form-data">
<table width="600" bgcolor="orange" align="center" border="10">
<tr>
<td align="center" bgcolor="yellow" colspan="6">
<h1>Edit The Post Here</h1>
</td>
</tr>
<tr>
<td align="right">Post Title:</td>
<td><input type="text" name="title" size="30" value="<?php echo $post_title; ?>"></td>
</tr>
<tr>
<td align="right">Post Author:</td>
<td><input type="text" name="author" size="30" value="<?php echo $post_author; ?>"></td>
</tr>
<tr>
<td align="right">Post Keywords:</td>
<td><input type="text" name="keywords" size="30" value="<?php echo $post_keywords; ?>"></td>
</tr>
<tr>
<td align="right">Post Image:</td>
<td>
<input type="file" name="image">
<img src="../images/<?php echo $post_image; ?>"width="100" height="100"></td>
</tr>
<tr>
<td align="right">Post Content:</td>
<td><textarea name="content" cols="30" rows="15"><?php echo $post_content; ?></textarea></td>
</tr>
<tr>
<td align="center" colspan="6"><input type="submit" name="update" id="update" value="Update Now"></td>
</tr>
</table>
</form>
</body>
</html>
<?php
if(isset($_POST['update'])) {
$update_id = $_GET['edit_form'];
$post_title1 = $_POST['title'];
$post_date1 = date('m-d-y');
$post_author1 = $_POST['author'];
$post_keywords1 = $_POST['keywords'];
$post_content1 = $_POST['content'];
$post_image1 = $_FILES['image']['name'];
$image_tmp = $_FILES['image']['tmp_name'];
if($post_title1 == '' or $post_author1=='' or $post_keywords1=='' or $post_content1=='' or $post_image1=='') {
echo "<script>alert('Any of the fields is empty')</script>";
exit();
}
else {
move_uploaded_file($image_tmp,"../images/$post_image1");
$update_query = "update posts set post_title='$post_title1', post_date='$post_date1', post_author='$post_author1',post_image='$post_image1',post_keywords='$post_keywords1',post_content='$post_content1' where post_id='$update_id'";
if(mysqli_query($con,$update_query)) {
echo "<script>alert('Post has been updated')</script>";
echo "<script>window.open('view_posts.php','_self')</script>";
}
}
}
?>
Here is the Error. It says undefined variable:

Answer 1

In my opinion, at the first you load script, everything is ok because you GET a page. At this time, isset($_GET['edit']) would true .
After you clicked update (I guess you submit page itself). At this point, isset($_GET['edit']) would false because you're doing POST. So, block code inside
if(isset($_GET['edit'])) {
.....
}
will be skipped. And those variables would be undefined.
Sorry for my english.