Simple

SELECT * FROM gallery2 WHERE topic_id="1048427" UNION SELECT * FROM gallery2 WHERE topic_id="1132676" UNION SELECT * FROM gallery2 WHERE topic_id="1709475" UNION SELECT * FROM gallery2 WHERE topic_id="1136901" UNION SELECT * FROM gallery2 WHERE topic_id="378364" UNION SELECT * FROM gallery2 WHERE topic_id="636871" UNION SELECT * FROM gallery2 WHERE topic_id="1409501" UNION SELECT * FROM gallery2 WHERE topic_id="766625" UNION SELECT * FROM gallery2 WHERE topic_id="290608" UNION SELECT * FROM gallery2 WHERE topic_id="1195604" UNION SELECT * FROM gallery2 WHERE topic_id="204543" UNION SELECT * FROM gallery2 WHERE topic_id="1086752" UNION SELECT * FROM gallery2 WHERE topic_id="1666070" UNION SELECT * FROM gallery2 WHERE topic_id="1738744" UNION SELECT * FROM gallery2 WHERE topic_id="1568597" UNION SELECT * FROM gallery2 WHERE topic_id="822067"