我在带有2个表的sqlserver中有这个查询(一个包含公司列表,第二个包含发布者列表)
with edges as (
select t1.company as node1, t2.company as node2
from table1 t1 join
table1 t2
on t1.publisher = t2.publisher
),
cte as (
select e.node1, e.node2,
cast('|'+e.node1+'|'+e.node2+'|' as varchar(max)) as nodes,
1 as level
from edges e
union all
select c.node1, e.node2,
c.nodes+e.node2+'|',
1+c.level
from cte c join
edges e
on c.node2 = e.node1 and
c.nodes not like '|%'+e.node2+'%|'
),
nodes as (
select node1,
(case when min(node2) < node1 then min(node2) else node1 end
) as grp
from cte
group by node1
)
select t.company, t.publisher, grp.GroupId
from table1 t join
(select n.node1, dense_rank() over (order by grp) as GroupId
from nodes n
) grp
on t.company = grp.node1;
我应该将此sqlserver查询转换为postgres