我有一个名为Data的数据库,如下所示:
ID | Name | Weakness1 | Weakness2 | Weakness3
_____________________________________________
1 | A | W1 | W2 | Null
2 | B | NULL | W2 | W3
3 | C | W1 | NULL | NULL
4 | A | W1 | W2 | W3
5 | A | W1 | NULL | NULL
我喜欢查询,因此可以显示如下:
Name | Weakness | Frequency
___________________________________
A | W1 | 3
A | W2 | 2
A | W3 | 1
请注意,同名可以具有不同的ID。到目前为止,我尝试了代码:
Select DISTINCT Name,
UNNEST(ARRAY[weakness1,weakness2,weakness3] as Weakness,
UNNESR(ARRAY[count(weakness1),count(weakness2),count(weakness2)])
from data
where agentname like '%A%'
GROUP by agentname,weakness1,weakness2,weakness3
我还显示了一个NULL行。在'where'之后不允许COUNT(Weakness1)> 0并且我得到的弱点是多余的,尽管我已经添加了'DISTINCT'
所以它显示如下:
Name | Weakness | Frequency
___________________________________
A | W1 | 1
A | | 0
A | W3 | 1
A | W1 | 2
A | W2 | 1
A | W2 | 1
这里有什么问题?谢谢
答案 0 :(得分:1)
你能尝试这样的事吗?
with data as (
select name, weakness1 as weakness from tablename
union all
select name, weakness2 as weakness from tablename
union all
select name, weakness3 as weakness from tablename
)
select name, weakness, count(*)
from data
where name like '%A%' and weakness is not null
group by name, weakness
结果
| name | weakness | count |
|------|----------|-------|
| A | W1 | 3 |
| A | W3 | 1 |
| A | W2 | 2 |
示例:http://sqlfiddle.com/#!15/7e4aa/3
替代方法:
select name, weakness, count(*) from (
select name, unnest(array[weakness1, weakness2, weakness3]) as weakness
from tablename
) t
where name like '%A%' and weakness is not null
group by name, weakness;
答案 1 :(得分:0)
SELECT NAME
,unnest(regexp_split_to_array(concat_ws(',', weak1, weak2, weak3), ',')) weakness
,count(unnest(regexp_split_to_array(concat_ws(',', weak1, weak2, weak3), ','))) frequency
FROM dat
WHERE NAME = 'A' -- or use WHERE NAME like '%A%'
GROUP BY 2,1
答案 2 :(得分:0)
找到这个
select Name,Weakness1 as weakness,count(Weakness1) from data
where name ='A' group by name,weakness1
Union all
select Name,Weakness2 as weakness,count(Weakness2) from data
where name ='A' and Weakness2 ='W2' group by name,weakness2
union all
select Name,Weakness3 as weakness,count(Weakness3) from data
where name ='A' and Weakness3 ='W3' group by name,weakness3