SELECT `idx`, `saved_file`, `uploaded_file`, `file_extension`, `file_size`, `download_count` FROM `board_file` WHERE `board_data_idx`=

There is an error in the transmitted query.
ERROR_CODE 1064 : You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near '' at line 1

SELECT `idx`, `subject`, `secret_flag`, `add_id` FROM `board_data` WHERE `board_id`='center' AND `idx`< AND `idx` NOT IN(5817, 5818) ORDER BY `idx` DESC LIMIT 1

There is an error in the transmitted query.
ERROR_CODE 1064 : You 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 `idx` NOT IN(5817, 5818) ORDER BY `idx` DESC LIMIT 1' at line 5

SELECT `idx`, `subject`, `secret_flag`, `add_id` FROM `board_data` WHERE `board_id`='center' AND `idx`> AND `idx` NOT IN(5817, 5818) ORDER BY `idx` ASC LIMIT 1

There is an error in the transmitted query.
ERROR_CODE 1064 : You 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 `idx` NOT IN(5817, 5818) ORDER BY `idx` ASC LIMIT 1' at line 5