SQL連續日-Oracle

Question

[數據]

[Emp] [Emp_group] [Date_purchase]
1      001         12-jan-2016
1      001         13-jan-2016
1      001         19-jan-2016
1      003         14-jan-2016
2      004         21-feb-2016
2      004         22-feb-2016
2      004         23-feb-2016
3      005         01-apr-2016

需要SQL查找連續的購買日期。 emp組（001）的Emp（1）已於1月12日和13日連續購買。 必須考慮Emp和Emp組分區。

Answer 1

只需使用lag() / lead() ：

select t.*
from (select t.*,
             lag(date_purchase) over (partition by emp, emp_group order by date_purchase) as prev_dp,
             lead(date_purchase) over (partition by emp, emp_group order by date_purchase) as next_dp
      from t
     ) t
where date_purchase in (prev_dp, next_dp);