sqlserver呼叫中心保留通话时长最长的记录

--在同一天之内，分机号相同，对方号码相同的，呼叫类型为呼出的通话记录，只保留通话时长最长的一条记录
--更具Id删除不是通话时长最长的记录

delete from RecordLogInfo where Id in(
--找到某段时间范围内，呼叫类型为呼出的不是最长的所有记录

select Id from RecordLogInfo where CtiCallType=1 and LogTime>='2012-10-01' and Id not in (
--为了找到通话时长最长的记录，第二步和第一步需要联合查询，找到最长记录的Id

select Id from 
(
--第二步：开始分组，发现分组后Id没有了

select AttendantPhoneNo,UserPhoneNo,LogTime,max(RecordDuration) as RecordDuration,count(*) as counts from (
--第一步：找到符合条件的记录

select AttendantPhoneNo,UserPhoneNo,RecordDuration,CONVERT(varchar(10), LogTime, 120) as LogTime from RecordLogInfo where CtiCallType=1 and LogTime>='2012-10-01') 
RecordLogInfo group by LogTime,AttendantPhoneNo,UserPhoneNo
) as a,(select Id,AttendantPhoneNo,UserPhoneNo,RecordDuration,CONVERT(varchar(10), LogTime, 120) as LogTime from RecordLogInfo where CtiCallType=1 and LogTime>='2012-10-01') as b
 where a.AttendantPhoneNo=b.AttendantPhoneNo and a.UserPhoneNo=b.UserPhoneNo and a.LogTime=b.LogTime and a.RecordDuration=b.RecordDuration
) 
)


--如果在拨打过程中按键则系统记录的电话号码的实际长度会增长，截取字段，这样才不会遗漏，最后根据查出来的Id删除数据

select Id from RecordLogInfo where CtiCallType=1 and LogTime>='2012-10-01' and Id not in (
select Id from 
(
select AttendantPhoneNo,substring(UserPhoneNo,1,12) as UserPhoneNo,LogTime,max(RecordDuration) as RecordDuration,count(*) as counts from (
select AttendantPhoneNo,substring(UserPhoneNo,1,12) as UserPhoneNo,RecordDuration,CONVERT(varchar(10), LogTime, 120) as LogTime from RecordLogInfo where CtiCallType=1 and LogTime>='2012-10-01' and len(substring(UserPhoneNo,1,12))=12) 
RecordLogInfo group by LogTime,AttendantPhoneNo,UserPhoneNo
) as a,(select Id,AttendantPhoneNo,substring(UserPhoneNo,1,12) as UserPhoneNo,RecordDuration,CONVERT(varchar(10), LogTime, 120) as LogTime from RecordLogInfo where CtiCallType=1 and LogTime>='2012-10-01' and len(substring(UserPhoneNo,1,12))=12) as b
 where a.AttendantPhoneNo=b.AttendantPhoneNo and a.UserPhoneNo=b.UserPhoneNo and a.LogTime=b.LogTime and a.RecordDuration=b.RecordDuration
)