将行转置为 teradata 中的列

Question

我有一个 table 如下所示

Date_value| Class_ID | count
17-05-2016|1         | 200
17-05-2016|2         | 400
17-05-2016|3         |250
17-05-2016|4         | 300
18-05-2016|1         | 500
18-05-2016|2         | 600
18-05-2016|3         |750
18-05-2016|4         | 800

现在我想要如下输出。

Date_value|1   |2   |3    |4
17-05-2016|200 |400 | 250 |300
18-05-2016|500 |600 | 750 |800

提前致谢，尼基拉

Answer 1

Teradata 中没有 PIVOT 函数，但这只是一些创建 Select 类似于此的语法：

select
   Date_value,
   sum(case when Class_ID = 1 then "count" end as "1",
   sum(case when Class_ID = 2 then "count" end as "2",
   sum(case when Class_ID = 3 then "count" end as "3",
   sum(case when Class_ID = 4 then "count" end as "4",
from tab
group by Date_value

将行转置为 teradata 中的列

transposing rows to columns in teradata

teradata