Find repeating rows

[Anon]

In MySQL, how can I find out if a mail adress in the mail column is recorded twice??

anyone?

[Anon]

select count() as adresses,mailcolumn
from mailtable
group by mailcolumn
having count() > 1

[Anon]

Thanks, is there anywhere in the MySQL manual where there are information about this?

[Anon]

$query = "select * from table";
$result = mysql_db_query("database",$query,$connect);

$check=0;
while($row = mysql_fetch_array($result))
{
$query2 = "select * from table";
$result2 = mysql_db_query("database",$query2,$connect);
while($ruw = mysql_fetch_array($result2))
{
if ($row[email] == $ruw[email])
$check++;
}
echo "$row[email] exists $check times";
}