mysql_num_rows() expects parameter 1 to be resource

Ta dando esse erro e eu nao tenho ideia de como arrumar. Alguem da uma luz pf

Warning: mysql_num_rows() expects parameter 1 to be resource, boolean given in /home/u572453808/public_html/eventos.php on line 232

Warning: mysql_fetch_array() expects parameter 1 to be resource, boolean given in /home/u572453808/public_html/eventos.php on line 239

Script:

$cmd = "SELECT * FROM test WHERE client <> '1' ORDER BY test DESC, test2 DESC" or die("<script>alert('ERROR404.*Server'); history.back();</script>");
 $eventos = mysql_query($cmd);
 $total = mysql_num_rows($eventos);
 $registros = 50;
 $numPaginas = ceil($total/$registros);
 $inicio = ($registros*$pagina)-$registros;
 $cmd = "select * FROM test WHERE client <> '1' ORDER BY test DESC, test2 Desc limit $inicio,$registros" or die("<script>alert('ERROR404.*Server'); history.back();</script>");
 $eventos = mysql_query($cmd);
 $total = mysql_num_rows($eventos);
 while ($evento = mysql_fetch_array($eventos)) {