-
-- 解法一
-
SELECT
-
t1.teacher_no,
-
(CASE WEEK WHEN '1' THEN keshuELSE 0END ) 礼拜一,
-
(CASE WEEK WHEN '2' THEN keshuELSE 0END ) 礼拜二,
-
(CASE WEEK WHEN '3' THEN keshuELSE 0END ) 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 keshuELSE 0END ) 礼拜一,
-
(CASE WEEK WHEN '2' THEN keshuELSE 0END ) 礼拜二,
-
(CASE WEEK WHEN '3' THEN keshuELSE 0END ) 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
-
;
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标题名称：(一)、根据teacher_no统计星期的上课数
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