假设只有4个级别,并且您总是希望从级别4开始,下面是查询
select L4.OSPID as L4OSPID, L4.OSPNAME as L4OPSNAME,
L4.RELATEDOSPID
as L3RELATEDID,
case
WHEN L3.OSPNAME = 'LEVEL3' THEN L3.OSPNAME
ELSE NULL
end as L3OSPNAME,
case
WHEN L3.OSPNAME = 'LEVEL3' THEN L3.RELATEDOSPID
ELSE NULL
end as L2RELATEDID,
case
WHEN L3.OSPNAME = 'LEVEL2' THEN L3.OSPNAME
WHEN L2.OSPNAME = 'LEVEL2' THEN L2.OSPNAME
ELSE NULL
end as L2OSPNAME,
case WHEN L3.OSPNAME = 'LEVEL2' THEN L3.RELATEDOSPID
WHEN L2.OSPNAME = 'LEVEL2' THEN L2.RELATEDOSPID
ELSE NULL
end
as L1RELATEDID,
case
WHEN L3.OSPNAME = 'LEVEL1' THEN L3.OSPNAME
WHEN L2.OSPNAME = 'LEVEL1' THEN L2.OSPNAME
WHEN L1.OSPNAME = 'LEVEL1' THEN L1.OSPNAME
ELSE NULL
end as L1OSPNAME,
case
WHEN L3.OSPNAME = 'LEVEL1' THEN L3.RELATEDOSPID
WHEN L2.OSPNAME = 'LEVEL1' THEN L2.RELATEDOSPID
WHEN L1.OSPNAME = 'LEVEL1' THEN L1.RELATEDOSPID
ELSE NULL
end as ROOTNODE
from osptable as L4
left outer join osptable as L3
on L4.RELATEDOSPID = L3.OSPID
left outer join osptable as L2
on L3.RELATEDOSPID = L2.OSPID
left outer join osptable as L1
on L2.RELATEDOSPID = L1.OSPID
where L4.OSPNAME = 'LEVEL4'
这给了我这个结果,我认为这是我想要的结果。
100004 LEVEL4 100003 LEVEL3 100002 LEVEL2 100001 LEVEL1 0
100009 LEVEL4 100008 NULL NULL LEVEL2 100007 NULL NULL
