How to Add and Delete users to a Web Database using PHP and MySql

So if you want to learn how to add and delete users to a Web Database using PHP and Mysql, consider reading this chapter out of: Learning PHP, MySQL, and Javascript, 1st Edition

I would not use this example on a Public website, but rather on a site where you want to administer a names or items table. For instance, I have forked the code here to have a public add where I do not give access to users to delete from the table. On my staging Table, I have used the code below to allow me to administer users from both an add and delete perspective. I found this code very useful to get up and running quickly. And I am a newbie.

Chapter 10
Accessing MySQL Using PHP > A Practical Example

10.2. A Practical Example

I am not going to add all the verbage from the chapter, but rather just the code.

First you'll need to create "login.php" with your DB particulars.

<?php // login.php
$db_hostname = 'localhost';
$db_database = 'nameofdb';
$db_username = 'nametologin';
$db_password = 'passauthen';
?>

Secondly, you then either edit the fields below to match a table you have or make a table with the fields author, title, category, year and ISBN. The rest is pretty simple. Or if it is not, you could read the whole chapter and be set.

<?php // sqltest.php
require_once 'login.php';
$db_server = mysql_connect($db_hostname, $db_username, $db_password);

if (!$db_server) die("Unable to connect to MySQL: " . mysql_error());

mysql_select_db($db_database, $db_server)
or die("Unable to select database: " . mysql_error());

if (isset($_POST['author']) &&
isset($_POST['title']) &&
isset($_POST['category']) &&
isset($_POST['year']) &&
isset($_POST['isbn']))
{
$author = get_post('author');
$title = get_post('title');
$category = get_post('category');
$year = get_post('year');
$isbn = get_post('isbn');

if (isset($_POST['delete']) && $isbn != "")
{
$query = "DELETE FROM classics WHERE isbn='$isbn'";

if (!mysql_query($query, $db_server))
echo "DELETE failed: $query<br />" .
mysql_error() . "<br /><br />";
}
else
{
$query = "INSERT INTO classics VALUES" .
"('$author', '$title', '$category', '$year', '$isbn')";

if (!mysql_query($query, $db_server))
echo "INSERT failed: $query<br />" .
mysql_error() . "<br /><br />";
}
}

echo <<<_END
<form action="sqltest.php" method="post"><pre>
Author <input type="text" name="author" />
Title <input type="text" name="title" />
Category <input type="text" name="category" />
Year <input type="text" name="year" />
ISBN <input type="text" name="isbn" />
<input type="submit" value="ADD RECORD" />
</pre></form>
_END;

$query = "SELECT * FROM classics";
$result = mysql_query($query);

if (!$result) die ("Database access failed: " . mysql_error());
$rows = mysql_num_rows($result);

for ($j = 0 ; $j < $rows ; ++$j)
{
$row = mysql_fetch_row($result);
echo <<<_END
<pre>
Author $row[0]
Title $row[1]
Category $row[2]
Year $row[3]
ISBN $row[4]
</pre>
<form action="sqltest.php" method="post">
<input type="hidden" name="delete" value="yes" />
<input type="hidden" name="isbn" value="$row[4]" />
<input type="submit" value="DELETE RECORD" /></form>
_END;
}

mysql_close($db_server);

function get_post($var)
{
return mysql_real_escape_string($_POST[$var]);
}
?>