根据teacher_no统计星期的上课数
发布时间：2022-03-30 10:42:57 所属栏目：搜索优化 来源：互联网
导读：根据teacher_no统计星期的上课数： -- 解法一 SELECT t1.teacher_no, (CASE WEEK WHEN 1 THEN keshu ELSE 0 END ) 礼拜一, (CASE WEEK WHEN 2 THEN keshu ELSE 0 END ) 礼拜二, (CASE WEEK WHEN 3 THEN keshu ELSE 0 END ) 礼拜三 FROM ( SELECT teacher_no,
 根据teacher_no统计星期的上课数： -- 解法一 SELECT t1.teacher_no, (CASE WEEK WHEN '1' THEN keshu ELSE 0 END ) 礼拜一, (CASE WEEK WHEN '2' THEN keshu ELSE 0 END ) 礼拜二, (CASE WEEK WHEN '3' THEN keshu ELSE 0 END ) 礼拜三 FROM ( SELECT teacher_no, WEEK, COUNT(1) AS keshu FROM teach GROUP BY teacher_no,WEEK )t1 GROUP BY t1.teacher_no; -- 解法二 就是count()函数作用 SELECT t1.teacher_no, (CASE WEEK WHEN '1' THEN keshu ELSE 0 END ) 礼拜一, (CASE WEEK WHEN '2' THEN keshu ELSE 0 END ) 礼拜二, (CASE WEEK WHEN '3' THEN keshu ELSE 0 END ) 礼拜三 FROM ( SELECT t.teacher_no, t.WEEK, COUNT(t.keshu) AS keshu FROM ( SELECT teacher_no, WEEK, '1' keshu FROM teach )t GROUP BY teacher_no,WEEK )t1 GROUP BY t1.teacher_no （编辑：温州站长网） 【声明】本站内容均来自网络，其相关言论仅代表作者个人观点，不代表本站立场。若无意侵犯到您的权利，请及时与联系站长删除相关内容! |
