[RESOLVED] Test the presence of a text in rows in DB

mrame

I need to check for the presence of a text say 'mrame' in the row values in DB. I do this by the below code. But the else part executes whenever $username !== $x. I don't want this to happen. My aim is to execute the else part only for the first time and also the while loop should stop once a else has executed.

$username = "mrame"; 
$ch=mysql_query("select USER_NAME from ADM_APP_USER_DTL;");

               $i=0;
               $rows=mysql_num_rows($ch);

              while($i < $rows)
                {
                $x = mysql_result($ch, $i, 0);


                    if($username==$x)
                    {
                    echo "User name already in use. Try another name.";
                    }
                else
                    {
echo "mrame is testing";
}

bradgrafelman

Can you tell us more about the big picture, here? Are you trying to INSERT a new row only if one with identical data doesn't already exist?

mrame

Yes absolutely. $ch gives a list of many user names. From that, I'm trying to check the presence of $username. If already present, I'm printing "User name already in use. Try another name.". Else, I have to insert that username to the DB.

kender

	$username_post = $_POST['USER_NAME'];
	$get_username = mysql_query("SELECT USER_NAME from ADM_APP_USER_DTL WHERE USER_NAME = '$username_post'") or die(mysql_error());
	if (mysql_num_rows($get_username) == 1) {
		echo '<p>That name is already in use, try again</p>'; // already registered
	} else {
		// do what you need to do to add user
	}

mrame

Many thanks kender. its working as I expected.

kender

Anytime, that is why we are here

Please remember to mark the thread as [Resolved]

bradgrafelman

The reason I asked is because there's a better solution; don't do any SELECT at all.

Since each username should be unique, add either a PRIMARY or UNIQUE key on the username column. That way, you would just do a normal INSERT query without checking first; if a duplicate row already exists, MySQL will throw a specific error message (number 1062, I believe) which you can check for using [man]mysql_errno/man.