私は従業員の履歴を取得するために複雑なSQLクエリが必要です

Question

従業員のID、たわごとと日付を含む従業員シフトテーブルが1つあります。 実際、私は毎日すべての従業員のシフトを入れています。表は1

Employee id  Shift  Date 
---------------------------------- 
1     G  2017-11-01 
1     G  2017-11-02 
1     NG  2017-11-03 
1     NG  2017-11-04 
1     G  2017-11-05 
1     G  2017-11-06 
1     G  2017-11-07 
1     G  2017-11-08 

以下のようにlooingされ、私は事前に

Employee Id  Shift From Date  To Date 
1     G  2017-11-01 2017-11-02 
1    NG  2017-11-03 2017-11-04 
1     G  2017-11-05 2017-11-08 

おかげで、以下のような出力が必要です。ループを使わずに簡単にログインできるようにしてください。

Answer 1

create table #merchant_comm(tid nvarchar(20), preval nvarchar(20), curval nvarchar(20), nextval nvarchar(20), datetimerequest datetime, nextdate datetime) 

truncate table #merchant_comm 

insert into #merchant_comm select * from (select tid,LAG(communication_mode) over (order by datetimerequest) preval, communication_mode curval, LEAD(communication_mode) over (order by datetimerequest) nextval,datetimerequest,LEAD(datetimerequest) over (order by datetimerequest) nextdate 
from MRLPOSNET_MSCRM.dbo.Pos_RL_communication_mode_Merchant_Detail 
where tid = '3734200M') as a 
where preval <> nextval or nextval is null or preval is null order by datetimerequest 


    with CTE as (
    select tid, 
case when preval is null then 1 when preval = curval then 0 when preval <> curval then 1 end as flag, 
curval as comm_mode, datetimerequest as from_date, lead(datetimerequest) over(order by datetimerequest) as to_date 
from #merchant_comm) 


select * from CTE where flag = 1