谁帮改改SQL语句，让更快执行

[liumang9527]

select ENTERPRISE_NUM ,
SUM(CASE WHEN status = 'A' then 1 else 0 end) ,
SUM(CASE WHEN status = 'Z' then 1 else 0 end)
from virtel_telrecord
where start_time>= '2006-8-2 10:35:12'
and sn not in
(select b.sn from virtel_telrecord b ,virtel_telrecord c
where b.source = c.source and b.dest = c.dest
and b.sn !=c.sn and b.status = 'Z'
and c.end_time = b.start_time)
group by ENTERPRISE_NUM

帮帮忙

[Limpire]

-- try

select a.ENTERPRISE_NUM ,
SUM(CASE WHEN a.status = 'A' then 1 else 0 end) ,
SUM(CASE WHEN a.status = 'Z' then 1 else 0 end)
from
virtel_telrecord a
left join
(select b.sn from virtel_telrecord b ,virtel_telrecord c
where b.source = c.source and b.dest = c.dest
and b.sn !=c.sn and b.status = 'Z'
and c.end_time = b.start_time) b
on a.sn = b.sn
where a.start_time >= '2006-8-2 10:35:12' and b.sn is null
group by a.ENTERPRISE_NUM