if(!($con = ssh2_connect("my_ssh_host", 22))){
    echo "fail: unable to establish connection\n";
} else {
    if(!ssh2_auth_password($con, "ssh_user", "ssh_password")) {
        echo "fail: unable to authenticate\n";
    } else {
        echo "okay: logged in...\n";
    }
}
if(!ssh2_tunnel($con, 'mysql_host', 3306 ))
{echo "<br/>fail tunnel";} else {echo "<br/> success tunnel<br/>";}
$tunnel=ssh2_tunnel($con, 'mysql_host', 3306 );
mysql_connect('127.0.0.1',$username,$password) or die ("СОЕДИНЕНИЕ НЕ УСТАНОВЛЕНО");

okay: logged in...
success tunnel
СОЕДИНЕНИЕ НЕ УСТАНОВЛЕНО

mysql_connect('localhost',$username,$password) or die ("СОЕДИНЕНИЕ НЕ УСТАНОВЛЕНО");

$conect = ssh2_exec($con, ' mysql -u  и так далее');

$consshsql = ssh2_exec($con, 'mysql -u sql_user -p -h sql_host sql_DB_name');

$conect = ssh2_exec($con, ' mysql -u NAMEUSER -p PASSWORD USE MyDataBase; INSERT INTO ..... ;  ');

$conect = ssh2_exec($con, ' mysql -u NAMEUSER -p PASSWORD USE MyDataBase; SELECT * FROM ..... ;  ');

if($consshsql = ssh2_exec($ssh_conn, 'ssh -L 3306:mysql_host:3306 mysql_user@localhost'))
{echo ('ssh2_exec - SUCCESS!');} else {echo ('ssh2_exec - DENIED');}