PHP, to store record into Database but check for records first

$ip=$_SERVER['REMOTE_ADDR'];//check IP
$sql = mysql_connect ('server', 'user','password')or die(mysql_error();//connect to database
$baza=mysql_select_db('IP_db')or die(mysql_error());//chose database

$sql_query = mysql_query("SELECT Ip FROM Ip_table WHERE Ip='$ip'")or die(mysql_error());//check IP in database
$rows=mysql_num_rows($sql_query);//how many find


if ($rows)//if IP exist in database
        {
	$sql_query = mysql_query("UPDATE Ip SET DATE=CURDATE()' WHERE Ip='$ip'");//update last visit date
        mysql_close($sql);//disconnect with database
        }
else//if IP does not exist in database
        {
        $sql_query = mysql_query("INSERT INTO Ip_table VALUES ('','$ip',CURDATE())")or die(mysql_error());//save IP in database
        mysql_close($sql);//disconnect with database        
        }