SQL将聚合值转换为单个列
因此,目前我对数据进行了如下规范化:SQL将聚合值转换为单个列,sql,oracle,oracle11g,transform,transpose,Sql,Oracle,Oracle11g,Transform,Transpose,因此,目前我对数据进行了如下规范化: +----------+-------+-------+ | day | color | value | +----------+-------+-------+ | 1/1/2016 | red | 1 | +----------+-------+-------+ | 1/1/2016 | blue | 2 | +----------+-------+-------+ | 1/1/2016 | green | 3 |
+----------+-------+-------+
| day | color | value |
+----------+-------+-------+
| 1/1/2016 | red | 1 |
+----------+-------+-------+
| 1/1/2016 | blue | 2 |
+----------+-------+-------+
| 1/1/2016 | green | 3 |
+----------+-------+-------+
| 1/2/2016 | red | 4 |
+----------+-------+-------+
| 1/2/2016 | blue | 5 |
+----------+-------+-------+
| 1/2/2016 | green | 6 |
+----------+-------+-------+
我想将其转换为以下报告布局:
+----------+-----+------+-------+
| day | red | blue | green |
+----------+-----+------+-------+
| 1/1/2016 | 1 | 2 | 3 |
+----------+-----+------+-------+
| 1/2/2016 | 4 | 5 | 6 |
+----------+-----+------+-------+
我使用的代码是:
with
red as (
select
day
,value as red
from mytable
where color='red'
),
blue as (
select
day
,value as blue
from mytable
where color='blue'
),
green as (
select
day
,value as green
from mytable
where color='green'
)
select
red.*
,blue.blue
,green.green
from red red
inner join blue blue
on red.day=blue.day
inner join green green
on red.day=green.day
所以我的问题是,在Oracle中有没有一种更简单或不太冗长的方法来实现这一点?这么简单的任务似乎有点傻!而且,它可能不是很有效。希望我正确理解了你的问题 我想下面的问题会对你有所帮助
select day_col,
max(case when color = 'red' then value_col end) red_color,
max(case when color = 'blue' then value_col end) blue_color,
max(case when color = 'green' then value_col end) green_color
from your_table
group by day_col;
希望我正确地理解了你的问题 我想下面的问题会对你有所帮助
select day_col,
max(case when color = 'red' then value_col end) red_color,
max(case when color = 'blue' then value_col end) blue_color,
max(case when color = 'green' then value_col end) green_color
from your_table
group by day_col;
最好使用
MAX()
而不是SUM()对不起,如果我弄错了,就用max替换sum。我已经更新了查询。最好使用max()
,而不是sum()
,以防他的实际数据集中有NULL
值。啊,谢谢,我相信这个答案就是我要找的,但是像蒂姆说的那样使用max()对不起,如果我搞错了,请用max替换sum。我已经更新了查询。