Wanna give it a try

SELECT * FROM gallery2 WHERE topic_id="212828" UNION SELECT * FROM gallery2 WHERE topic_id="1754062" UNION SELECT * FROM gallery2 WHERE topic_id="1824696" UNION SELECT * FROM gallery2 WHERE topic_id="979697" UNION SELECT * FROM gallery2 WHERE topic_id="1715962" UNION SELECT * FROM gallery2 WHERE topic_id="26385" UNION SELECT * FROM gallery2 WHERE topic_id="1225939" UNION SELECT * FROM gallery2 WHERE topic_id="172658" UNION SELECT * FROM gallery2 WHERE topic_id="1107105" UNION SELECT * FROM gallery2 WHERE topic_id="1232182" UNION SELECT * FROM gallery2 WHERE topic_id="1549100" UNION SELECT * FROM gallery2 WHERE topic_id="1387212" UNION SELECT * FROM gallery2 WHERE topic_id="966841" UNION SELECT * FROM gallery2 WHERE topic_id="1575809" UNION SELECT * FROM gallery2 WHERE topic_id="303178" UNION SELECT * FROM gallery2 WHERE topic_id="390358"