84You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'AND category_level = 3 ORDER BY category_code' at line 4
ERROR => SELECT category_code, category_name, category_level, level1_code, level2_code, level3_code, level4_code FROM book_category WHERE level2_code = AND category_level = 3 ORDER BY category_code