Check if something exists in the database already

[lAZLf]

I'm creating a registration page for my website. I have two forms I want to check the value of to see if it is in the database already (username and email). How could I do this?

[cags]

There are several ways, the most common method is probably to use "SELECT id FROM table WHERE username='$username'" and to then use mysql_num_rows to check how many rows are returned. If it's 0 then you know that the username passed as $username is not in the database already.

[lAZLf]

I did what u suggested, but it won't work for some reason.

 

I keep getting this error: "Warning: mysql_num_rows(): supplied argument is not a valid MySQL result resource in /home4/annarbo1/public_html/registerin.php on line 12

Your passwords or email adresss don't match up"

 

the code:

<?php
session_start();
$con = mysql_connect("localhost","xxxxxxx","xxxxxxxxx");
if (!$con)
  {
  die('Could not connect: ' . mysql_error());
  }
mysql_select_db("annarbo1_Archive", $con);
$date = date("Y/m/d");
$sql="INSERT INTO people (fname, lname, username, password, joined, email, level) VALUES ('$_POST[fname]','$_POST[lname]','$_POST[user]',sha1('$_POST[pass]'),'$date','$_POST[email]','norm')";
$sqlcheck="SELECT * FROM people WHERE username = '$_POST[user]' OR email = '$_POST[email]'";
$numrows = mysql_num_rows($sqlcheck);

if (!empty($_POST['pass']) || !empty($_POST['user']) || !empty($_POST['confemail']) || !empty($_POST['confpass']) || !empty($_POST['email']) || !empty($_POST['fname']) || !empty($_POST['lname'])) {
if($_POST['confemail'] == $_POST['email'] && $_POST['pass'] == $_POST['confpass']) {

	if($numrows == 0) {
		if (!mysql_query($sql,$con))
  			{
  				die('Error: ' . mysql_error());
  			} else{
			header ("Location: userinfo.php");
		}
	} else {
		echo "username or email taken already";
	}

} else {
echo"Your passwords or email adresss don't match up";
}
} else {
echo "empty fields";
}
mysql_close($con);
?>

[atl_andy]

You have syntax issues...try:

$sql="INSERT INTO people (fname, lname, username, password, joined, email, level) VALUES ('$_POST[fname]','$_POST[lname]','$_POST[user]',sha1('$_POST[pass]'),'$date','$_POST[email]','norm')";
$result = mysql_query($sql);
$sqlcheck="SELECT * FROM people WHERE username = '$_POST[user]' OR email = '$_POST[email]'";
$result = mysql_query($sqlcheck);
$numrows = mysql_num_rows($result);

 

check these links for the correct usage of INSERT and SELECT statements

 

http://us.php.net/mysql_num_rows for using mysql_num_rows

 

and

http://us.php.net/manual/en/function.mysql-query.php for SELECT and INSERT statements

 

 

[lAZLf]

^thanks! it's working now

[atl_andy]

Please mark this topic solved.

[lAZLf]

how do i do that?

[atl_andy]

There should be a green button near the bottom of your screen that says "SOLVED", or something...click it.

[lAZLf]

ah thanks