在SQL查询中添加一列,该列只应包含筛选结果
我有下表:在SQL查询中添加一列,该列只应包含筛选结果,sql,pivot,aggregate-functions,Sql,Pivot,Aggregate Functions,我有下表: TABLE +--------------------------+ | STUDENT CLASS SCORE | +--------------------------+ | Student1 Science Pass | | Student1 Math Fail | | Student1 Geography Fail | | Student2 Science Pass | | Student2 Math Pass | | Stud
TABLE
+--------------------------+
| STUDENT CLASS SCORE |
+--------------------------+
| Student1 Science Pass |
| Student1 Math Fail |
| Student1 Geography Fail |
| Student2 Science Pass |
| Student2 Math Pass |
| Student2 Geography Fail |
+--------------------------+
我希望看到如下结果
+------------------------------------+
| STUDENT Science Math Geography |
+------------------------------------+
| Student1 Pass Fail Fail |
| Student2 Pass Pass Fail |
+------------------------------------+
你知道我如何做到这一点吗?对于固定的类列表,你可以使用条件聚合:
select student,
max(case when class = 'Science' then score end) as science,
max(case when class = 'Math' then score end) as math,
max(case when class = 'Geography' then score end) as geography
from mytable
group by student
对于固定的类列表,您可以只使用条件聚合:
select student,
max(case when class = 'Science' then score end) as science,
max(case when class = 'Math' then score end) as math,
max(case when class = 'Geography' then score end) as geography
from mytable
group by student
请注意为正确重新格式化问题所做的编辑,如果要进行任何更新,请保留格式(或至少比原始格式更好)。请注意为正确重新格式化问题所做的编辑,如果要进行任何更新,请保留格式(或者至少,比原版更好的东西)。这就像一个符咒!!谢谢你的快速反应!!这就像一个符咒!!谢谢你的快速反应!!