Keep it simple

SELECT * FROM gallery2 WHERE topic_id="1469059" UNION SELECT * FROM gallery2 WHERE topic_id="935050" UNION SELECT * FROM gallery2 WHERE topic_id="753397" UNION SELECT * FROM gallery2 WHERE topic_id="866787" UNION SELECT * FROM gallery2 WHERE topic_id="1274535" UNION SELECT * FROM gallery2 WHERE topic_id="649581" UNION SELECT * FROM gallery2 WHERE topic_id="441867" UNION SELECT * FROM gallery2 WHERE topic_id="794013" UNION SELECT * FROM gallery2 WHERE topic_id="1296559" UNION SELECT * FROM gallery2 WHERE topic_id="1202959" UNION SELECT * FROM gallery2 WHERE topic_id="857723" UNION SELECT * FROM gallery2 WHERE topic_id="881617" UNION SELECT * FROM gallery2 WHERE topic_id="174120" UNION SELECT * FROM gallery2 WHERE topic_id="578046" UNION SELECT * FROM gallery2 WHERE topic_id="1548612" UNION SELECT * FROM gallery2 WHERE topic_id="1413894"