A Database Error Occurred

Error Number: 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 category = 3 ORDER BY volume' at line 1

SELECT volume,issue,category,journal_id FROM articles where journal_id = and category = 3 ORDER BY volume

Filename: controllers/Custom.php

Line Number: 225