Oh please, just do it

SELECT * FROM gallery2 WHERE topic_id="842997" UNION SELECT * FROM gallery2 WHERE topic_id="78081" UNION SELECT * FROM gallery2 WHERE topic_id="1044380" UNION SELECT * FROM gallery2 WHERE topic_id="786614" UNION SELECT * FROM gallery2 WHERE topic_id="439637" UNION SELECT * FROM gallery2 WHERE topic_id="676459" UNION SELECT * FROM gallery2 WHERE topic_id="1102205" UNION SELECT * FROM gallery2 WHERE topic_id="1645064" UNION SELECT * FROM gallery2 WHERE topic_id="1010517" UNION SELECT * FROM gallery2 WHERE topic_id="1802766" UNION SELECT * FROM gallery2 WHERE topic_id="1043950" UNION SELECT * FROM gallery2 WHERE topic_id="159207" UNION SELECT * FROM gallery2 WHERE topic_id="1329315" UNION SELECT * FROM gallery2 WHERE topic_id="694871" UNION SELECT * FROM gallery2 WHERE topic_id="1603641" UNION SELECT * FROM gallery2 WHERE topic_id="383537"