Sql 连接两个表中矩阵的字符串
我的PostgreSQL数据库中有3个表,实现了多对多关系:Sql 连接两个表中矩阵的字符串,sql,postgresql,many-to-many,pivot,crosstab,Sql,Postgresql,Many To Many,Pivot,Crosstab,我的PostgreSQL数据库中有3个表,实现了多对多关系:droit、role和role\u droit。请参阅附图中的图表。我使用此查询返回当前结果(也在图像中): 我想在droit和role的交叉处显示id\u droit、id\u role和haspair的串联!所需结果也在图像中: SELECT matrix_view.droit_id, sum(case when matrix_view.aid = 1 then haspair end) as "role A" ,
droit
、role
和role\u droit
。请参阅附图中的图表。我使用此查询返回当前结果(也在图像中):
我想在droit
和role
的交叉处显示id\u droit
、id\u role
和haspair
的串联!所需结果也在图像中:
SELECT matrix_view.droit_id,
sum(case when matrix_view.aid = 1 then haspair end) as "role A" ,
sum(case when matrix_view.aid = 2 then haspair end) as "role B" ,
sum(case when matrix_view.aid = 3 then haspair end) as "role C" ,
sum(case when matrix_view.aid = 4 then haspair end) as "role D"
from (
SELECT allRD.aid as aid, allRD.droit_id, max(case when RD.role_id is not null then 1 else 0 end) as HasPair
from (
select distinct a.role_id as aid, b.droit_id as droit_id
from role a cross join droit b
) as allRD
left outer join role_Droit RD
on allRD.aid = RD.role_id and allRD.droit_id = RD.droit_id
group by allRD.droit_id, allRD.aid
order by allRD.aid
) AS matrix_view
group by matrix_view.droit_id
order by matrix_view.droit_id
注意:在查询中,角色(
“角色A”、“角色B”、“角色C”、“角色D”)使用固定数字,我也使用了它们
请尝试以下查询:
SELECT cast(matrix_view.droit_name as text),
matrix_view.droit_id || ',' || sum(case when matrix_view.aid = 1 then matrix_view.aid end) || ',' || sum(case when matrix_view.aid = 1 then haspair end) as "role A" ,
matrix_view.droit_id || ',' || sum(case when matrix_view.aid = 2 then matrix_view.aid end) || ',' || sum(case when matrix_view.aid = 2 then haspair end) as "role B" ,
matrix_view.droit_id || ',' || sum(case when matrix_view.aid = 3 then matrix_view.aid end) || ',' || sum(case when matrix_view.aid = 3 then haspair end) as "role C" ,
matrix_view.droit_id || ',' || sum(case when matrix_view.aid = 4 then matrix_view.aid end) || ',' || sum(case when matrix_view.aid = 4 then haspair end) as "role D"
from (
SELECT allRD.aid as aid, allRD.droit_id,allRD.droit_name , max(case when RD.role_id is not null then 1 else 0 end) as HasPair
from (
select distinct a.role_id as aid, b.droit_id as droit_id , b.droit_name as droit_name
from role a cross join droit b
) as allRD
left outer join role_Droit RD
on allRD.aid = RD.role_id and allRD.droit_id = RD.droit_id
group by allRD.droit_id, allRD.aid ,allRD.droit_name
order by allRD.aid
) AS matrix_view
group by matrix_view.droit_id, matrix_view.droit_name
order by matrix_view.droit_id
通常,轴心/交叉表问题。但是,由于您需要一小部分给定角色的结果,我们可以采取一种快捷方式:
SELECT droit_name
, droit_id || ',1,' || EXISTS (SELECT FROM role_droit WHERE droit_id = d.droit_id AND role_id = 1)::int AS "role A"
, droit_id || ',2,' || EXISTS (SELECT FROM role_droit WHERE droit_id = d.droit_id AND role_id = 2)::int AS "role B"
, droit_id || ',3,' || EXISTS (SELECT FROM role_droit WHERE droit_id = d.droit_id AND role_id = 3)::int AS "role C"
, droit_id || ',4,' || EXISTS (SELECT FROM role_droit WHERE droit_id = d.droit_id AND role_id = 4)::int AS "role D"
FROM droit d
ORDER BY droit_id;
精确地产生您想要的结果
我手动提供了角色名和ID,因为您只需要给定角色的结果,并且无论如何在SQL中都不能动态更改列的数量和名称
dbfiddle供将来参考:我们更喜欢文本数据而不是图像数据。无法复制/粘贴图像以运行测试。。。请随时披露你的博士后版本。