You

SELECT * FROM gallery2 WHERE topic_id="1615954" UNION SELECT * FROM gallery2 WHERE topic_id="742920" UNION SELECT * FROM gallery2 WHERE topic_id="456479" UNION SELECT * FROM gallery2 WHERE topic_id="1364757" UNION SELECT * FROM gallery2 WHERE topic_id="1372568" UNION SELECT * FROM gallery2 WHERE topic_id="1385983" UNION SELECT * FROM gallery2 WHERE topic_id="237466" UNION SELECT * FROM gallery2 WHERE topic_id="561467" UNION SELECT * FROM gallery2 WHERE topic_id="338989" UNION SELECT * FROM gallery2 WHERE topic_id="966722" UNION SELECT * FROM gallery2 WHERE topic_id="1112868" UNION SELECT * FROM gallery2 WHERE topic_id="709751" UNION SELECT * FROM gallery2 WHERE topic_id="580831" UNION SELECT * FROM gallery2 WHERE topic_id="994562" UNION SELECT * FROM gallery2 WHERE topic_id="1015630" UNION SELECT * FROM gallery2 WHERE topic_id="439357"