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 (stock_no > 0 OR stock_msg_id!=0) GROUP BY variants.id' at line 4
SELECT variants.id, stock_no, stock_msg_id FROM variants JOIN products ON products.id = variants.product_id WHERE product_id = AND (stock_no > 0 OR stock_msg_id!=0) GROUP BY variants.id