A PHP Error was encountered

Severity: Notice

Message: Trying to get property of non-object

Filename: controllers/inventory.php

Line Number: 428

A PHP Error was encountered

Severity: Notice

Message: Trying to get property of non-object

Filename: controllers/inventory.php

Line Number: 428

A Database Error Occurred

Error Number: 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 'AND rightval > ORDER BY rightval ASC' at line 3

SELECT * FROM categories WHERE leftval < AND rightval > ORDER BY rightval ASC