How to post data to mySQL database through PHP form?

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!

Notice: This code is vulnerable to SQL-Injection. You also should not use the deprecated mysql-lib anymore. Use mysqli or PDO instead. — AbcAeffchen
– AbcAeffchen, Commented Oct 18, 2015 at 23:35

AbcAeffchen · Accepted Answer · 2015-10-18 23:34:02Z

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."')";

edited Oct 18, 2015 at 23:34

AbcAeffchen

15.1k15 gold badges52 silver badges67 bronze badges

answered Oct 18, 2015 at 23:15

Programmatistis

463 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

How to post data to mySQL database through PHP form?

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related