Database error: [MySQL server has gone away]

SELECT a.*, b.post_content FROM ac_posts a INNER JOIN ac_posts_content b ON a.ID = b.ID WHERE a.ID IN(4935,5293,179,1681,4815,748,2306,761,1087,1553,5485,2,361,612,771,844,911,956,972,1100) ORDER BY FIELD(a.ID, 4935,5293,179,1681,4815,748,2306,761,1087,1553,5485,2,361,612,771,844,911,956,972,1100);