SELECT b2.job, b2.first_year_mon, b2.cnt AS first_year_cnt, b2.second_year_mon, b3.second_year_cnt FROM ( SELECT b1.job, DATE_FORMAT(b1.first_year_mon,'%Y-%m') AS first_year_mon, DATE_FORMAT(b1.second_year_mon,'%Y-%m') AS second_year_mon, SUM(b1.num) AS cnt FROM ( SELECT...