Tanya Error Warning: mysql_fetch_array() expects dan Warning: mysql_num_rows()

Assalamualaikum, saya ingin bertanya bagaimana ya cara mengatasi Warning: mysql_fetch_array() expects parameter 1 to be resource, boolean given in C:\xampp\htdocs\pegawai\config.php on line 23 dan Warning: mysql_num_rows() expects parameter 1 to be resource, boolean given in C:\xampp\htdocs\pegawai\config.php on line 22