这个sql如何优化？

带头大哥 2012-05-31 05:29:52

select c.cabName,r.motorName ,
(
select
p.poolName
from
NodeInfo n,PoolInfo p,Pool_node pn
where
n.nodeID = ?
and
p.poolID=pn.poolID
and
pn.nodeID =n.nodeID
)
as
poolName, n.* from NodeInfo n,CabinetInfo c, MotorRoomInfo r
where
n.nodeID = 6 and n.cabinetID =c.cabinetID and c.roomID = r.roomID;

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槑党--一缕风 2012-06-01

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(

select  

p.poolName  

from  

NodeInfo n,PoolInfo p,Pool_node pn  

where  

n.nodeID = ?  

and

p.poolID=pn.poolID  

and

pn.nodeID =n.nodeID

)

把这段放到外面来，这样每查询一条数据就执行一次，肯定会很慢

fox110112 2012-06-01

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select c.cabName,r.motorName ,t.poolName, n.*
from NodeInfo n,CabinetInfo c, MotorRoomInfo r ,
(
select
p.poolName ,n.nodeID
from
NodeInfo n,PoolInfo p,Pool_node pn
where

and
p.poolID=pn.poolID
and
pn.nodeID =n.nodeID
) t
where
n.nodeID = 6 and n.cabinetID =c.cabinetID and c.roomID = r.roomID
and t.nodeID=n.nodeID;