Check if user exists in db?

[genieuk]

Hi,

could someone tell me what the correct syntax is to check is a user exists in my database.

I got a login page and when user enters username and password i need it to check if they exist obviously in database and if so re-direct them to the page i specify else tell them login details don't exist.

Anyone be able to help me please?

thank you,
genieuk

[timmah]

Hi,

could someone tell me what the correct syntax is to check is a user exists in my database.

I got a login page and when user enters username and password i need it to check if they exist obviously in database and if so re-direct them to the page i specify else tell them login details don't exist.

Anyone be able to help me please?

thank you,
genieuk

So, in essence, you want a login script?

$config_basedir = "http://www.yoursite.com";
$user = mysql_real-escape_string($_POST['email']);
$password = mysql_real-escape_string($_POST['password']);

$loginsql = "SELECT * FROM main WHERE email = '$user' AND password = '$password'";
$loginres = mysql_query($loginsql);
$numrows = mysql_num_rows($loginres);
		
if($numrows == 1){				
$loginrow = mysql_fetch_assoc($loginres);
								
$_SESSION['SESS_LOGGEDIN'] = 1;
$_SESSION['SESS_NAME'] = $loginrow['username'];

//If login is correct					
header("Location: " . $config_basedir . "/index.php");
}
else {

//if login is incorrect
header("Location: " . $config_basedir . "/login.php?error=2");
}

Then you can put this where to show the errors

<?php

switch($_GET['error']) {
		
case "1":
echo "<font color='#FF0000'>You must be logged in.</font>";
break;
			
case "2":
echo "<font color='#FF0000'><strong>Incorrect username/password</strong></font>";
break;				
}
?>

[genieuk]

Thank you very much, i want to do it myself thou as i am learning, best way to learn and get wirting scripts is doing it myself. But thanks ever so much for your kindness.

I should have been more clear, the point of all this is for me to learn and learn from my mistakes.

Here is my code, i am not sure what i am doing wrong. To my knowledge 1 equals true and 0 equals false.

Please take a look and let me know what is wrong, i am doing it very basic then i will be adding cookies etc in future i am only doing it to learn then when i learn more i will eventually re-write the scripts to be less code and more efficent, bt as a newbie i am obviously on a big rollercoaster learning. It connects to DB etc but dont search for the info to see if it exists.

<?php include("db_connect.php"); // Database Connection ?>

<?php

if (isset($_POST['submitted'])) { // Handle the form.

$username = htmlspecialchars( stripslashes( strip_tags($_POST['username'] ) ) );
$password = htmlspecialchars( trim($_POST['password'] ) );
$url = "http://wwww.bbbb.com/cp.php";

if ( empty ($_POST['username'] ) ) { // Check if username field is empty. If it is tell them
	echo "<font color=\"#FF3F00\" face=\"Verdana, Geneva, sans-serif\"><p>Please Enter your Username in order to login.</p></font>";
}

if ( empty ($_POST['password'] ) ) { // Check if password field is empty. If it is tell them
	echo "<font color=\"#FF3F00\" face=\"Verdana, Geneva, sans-serif\"><p>Please Enter the Password associated with your account.</p></font>";
}

	
$query = mysql_query("SELECT * FROM userinformation WHERE username = '$username' AND 'password' = '$password'");
if( mysql_num_rows( $query ) == 1 ) {
    echo "<font color=\"#FF3F00\" face=\"Verdana, Geneva, sans-serif\"><p>Login Successful</p></font>"; 
	header("location: $url");
}

    else if (mysql_num_rows($query) == 0 ){
		
		echo "Login Details Incorrect, Please try again";
}
}

?>
<h1><font color="#007FAA" face="Verdana, Geneva, sans-serif">Login</font></h1>
<form action="login.php" method="post">
<center><p>Username:</p> <input type="text" name="username" size="20" maxlength="20" value="<?php if (isset($_POST["username"])) { echo htmlspecialchars($_POST["username"]); } ?>" />
<p>Password:</p> <input type="password" name="password" size="20" maxlength="20" />
<p> <input type="hidden" name="submitted" value="TRUE" /></p>
<p><input type="submit" value="Login" /></p></center>
</form>

thank you
genieuk