sql问题–case-when

1、 有表如下,请使用查询语句得出相应结果

id

job

createdate

1

开发

2018-06-19

2

运维

2018-06-20

3

开发

2018-06-19

4

开发

2018-06-20

得出如下结果

createdate

开发

运维

2018-06-19

2

0

2018-06-20

1

1

 

答案:

         SELECT

         aa.createdate,

         SUM(

                  CASE

                  WHEN aa.job = ‘开发‘ THEN

                          1

                  ELSE

                          0

                  END

         ) ‘开发‘,

         SUM(

                  CASE

                  WHEN aa.job = ‘运维‘ THEN

                          1

                  ELSE

                          0

                  END

         ) ‘运维‘

FROM

                  testtable aa

GROUP BY

                  aa.createdate;

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