How to post data to mySQL database through PHP form? - php

Question

I am new to PHP and I am following a tutorial that gets information from a mySQL database table by the row and outputs a form to create new table rows. For some reason I can't figure out what is wrong with my code? The page is blank when I refresh the page and I have been staring at this code forever. Does anybody know what I am doing wrong? The database connection is fine as it is used on another page and i have checked.
The mySQL database I have is extremely simple, with 1 table called users that has 5 columns (ID, username, firstName, lastName, title) with the ID being a unique field.
<?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['delete']) && isset($_POST['ID']))
{
$id = get_post('ID');
$query = "DELETE FROM users WHERE ID='$id'";
if (!mysql_query($query, $db_server))
echo "DELETE failed: $query<br>" .
mysql_error() . "<br><br>";
}
if (isset($_POST['ID']) &&
isset($_POST['username']) &&
isset($_POST['firstName']) &&
isset($_POST['lastName']) &&
isset($_POST['title']))
{
$id = get_post('ID');
$username = get_post('username');
$firstName = get_post('firstName');
$lastName = get_post('lastName');
$title = get_post('title');
$query = "INSERT INTO users VALUES" .
"('$id', '$username', '$firstName', '$lastName', '$title')";
if (!mysql_query($query, $db_server))
echo "INSERT failed: $query<br>" .
mysql_error() . "<br><br>";
}
echo <<<_END
<form action="sqltest.php" method="post"><pre>
ID <input type="text" name="ID">
username <input type="text" name="username">
firstName <input type="text" name="firstName">
lastName <input type="text" name="lastName">
title <input type="text" name="title">
<input type="submit" value="ADD RECORD">
</pre></form>
_END;
$query = "SELECT * FROM users";
$result = mysql_query($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>
ID $row[0]
username $row[1]
firstName $row[2]
lastName $row[3]
title $row[4]
</pre>
<form action="sqltest.php" method="post">
<input type="hidden" name="delete" value="yes">
<input type="hidden" name="title" value="$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]);
}
Any help would be super awesome!

Answer 1

You are trying to retrieve variables with the wrong way.
Example
$username = get_post('username');
should be
$username = $_POST['username'];
You should do the same with the same code that you are trying to retrieve post variables.
And the query to insert values should be
$query = "INSERT INTO users VALUES('".$id."', '".$username."', '".$firstName."', '".$lastName."', '".$title."')";