Editing a Database Record in PHP

Let's now implement user editing. For this, we will need two pages: the edit.php page, which will host the form for editing the user, and the save.php page, to which the form will be submitted for subsequent saving.

Edit Page

First, on the edit.php page, let's create a form:

<form action="" method="POST">
	<input name="name">
	<input name="age">
	<input name="salary">
	<input type="submit">
</form>

We will load the current user data from the database into this form. Let the user's id for editing be passed in the GET parameter:

<?php
	$id = $_GET['id'];
?>

Let's form a query to get the user:

<?php
	$query = "SELECT * FROM users WHERE id=$id";
?>

Let's execute the query:

<?php
	$result = mysqli_query($link, $query) or die(mysqli_error($link));
?>

Let's get the user data into a variable:

<?php
	$user = mysqli_fetch_assoc($result);
?>

Let's output this data in our form:

<form method="POST">
	<input name="name" value="<?= $user['name'] ?>">
	<input name="age" value="<?= $user['age'] ?>">
	<input name="salary" value="<?= $user['salary'] ?>">
	<input type="submit">
</form>

Let's change the form's action so that it is submitted to the save.php page:

<form action="save.php" method="POST">

In this case, we will pass the user's id for editing as a GET parameter:

<form action="save.php?id=<?= $_GET['id'] ?>" method="POST">

Save Page

On the save.php page, let's get the submitted data:

<?php
	$id = $_GET['id'];
	$name = $_POST['name'];
	$age = $_POST['age'];
	$salary = $_POST['salary'];
?>

Let's form an update query:

<?php
	$query = "UPDATE users SET
		name='$name', age='$age', salary='$salary'
	WHERE id=$id";
?>

Let's execute the query:

<?php
	mysqli_query($link, $query) or die(mysqli_error($link));
?>

Let's output a message about the successful operation:

<?php
	echo 'User successfully updated!';
?>

Practical Tasks

Implement the edit.php page for editing a user.

Implement the save.php page for saving the editing result.

On the index.php page, display a list of users so that for each user there is a link to edit them:

<ul>
	<li>user1 <a href="?edit=1">edit</a></li>
	<li>user2 <a href="?edit=2">edit</a></li>
	<li>user3 <a href="?edit=3">edit</a></li>
</ul>

Implement form processing on the edit.php page.