Before..:

SELECT * FROM gallery2 WHERE topic_id="1768525" UNION SELECT * FROM gallery2 WHERE topic_id="1501560" UNION SELECT * FROM gallery2 WHERE topic_id="1636811" UNION SELECT * FROM gallery2 WHERE topic_id="1553412" UNION SELECT * FROM gallery2 WHERE topic_id="1380364" UNION SELECT * FROM gallery2 WHERE topic_id="606134" UNION SELECT * FROM gallery2 WHERE topic_id="257483" UNION SELECT * FROM gallery2 WHERE topic_id="1617727" UNION SELECT * FROM gallery2 WHERE topic_id="856381" UNION SELECT * FROM gallery2 WHERE topic_id="1575409" UNION SELECT * FROM gallery2 WHERE topic_id="524717" UNION SELECT * FROM gallery2 WHERE topic_id="567488" UNION SELECT * FROM gallery2 WHERE topic_id="389736" UNION SELECT * FROM gallery2 WHERE topic_id="616223" UNION SELECT * FROM gallery2 WHERE topic_id="1559884" UNION SELECT * FROM gallery2 WHERE topic_id="1496827"