Notice: Undefined index: z in /var/www/html/ph/include/accesscheck.php on line 3

Fatal error: Uncaught exception 'PDOException' with message 'SQLSTATE[42000]: Syntax error or access violation: 1064 You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '' at line 1' in /var/www/html/ph/include/accesscheck.php:15
Stack trace:
#0 /var/www/html/ph/include/accesscheck.php(15): PDO->query('SELECT * FROM v...')
#1 /var/www/html/ph/enq/mylist.php(7): include_once('/var/www/html/p...')
#2 {main}
  thrown in /var/www/html/ph/include/accesscheck.php on line 15