Question

考虑示例表名“Person”。

Name    |Date   |Work_Hours
---------------------------
John|   22/1/13     |0
John|   23/1/13     |0
Joseph| 22/1/13     |1
Joseph| 23/1/13     |1
Johnny| 22/1/13     |0
Johnny| 23/1/13     |0
Jim|    22/1/13     |1
Jim|    23/1/13     |0

在上表中，我必须在Work_Hours列中找到序列为'0'后跟'1'的行。请分享想法/查询来做到这一点。

我需要的输出是

Name    |Date   |Work_Hours
---------------------------
John|   23/1/13     |0
Joseph| 22/1/13     |1
Johnny| 23/1/13     |0
Jim|    22/1/13     |1

Answer 1

有点像

select no_hours.Name, no_hours.Date, some_hours.Date
From Person no_hours
inner join Person some_hours 
On no_hours.Name = some_hours.name and some_hours.Date > no_hours.date
Where no_hours.work_hours = 0 and some_hours.work_hours = 1

将是一个开始。

毋庸置疑，名称不是一个好的唯一标识符......

也会出现工作时间从0到1到0，0到1到0到1会出现很多......

如果你可以在同一天从0到1，那么＆gt; = no_hours.date。

Answer 2

也许：

SELECT p1.Name, 
       p1.Date AS Date_1, 
       p2.Date AS Date_2, 
       p1.Work_Hours As Work_Hours_1,
       p2.Work_Hours As Work_Hours_2
FROM Person p1
INNER JOIN Person p2
  on p1.Name=p2.Name 
  AND p1.Work_Hours=0
  AND p2.Work_Hours=1
ORDER BY p1.Name,p1.Date,p2.Date,Work_Hours_1,Work_Hours_2

Demo

Answer 3

你的问题（如措辞）等同于问：1是否跟随任何给定行，name为0？

你可以做一个相关的子查询：

select Name, Date, Work_Hours
from (select t.*,
             (select min(date)
              from table t2
              where t2.name = t.name and t2.date > t.date and t2.Work_Hours = 1
             ) as DateOfLater1
      from table t
     ) t
where DateOfLater1 is not null and work_hours = 0 or
      (DateOfLater1 = date and work_hours = 1);

Answer 4

要查看以前或以后的记录，通常会使用聚合函数LAG和LEAD：

select first_name, work_date, work_hours
from
(
  select first_name, work_date, work_hours
    , lag(work_hours) over (order by first_name, work_date) as prev_work_hours
    , lead(work_hours) over (order by first_name, work_date) as next_work_hours
  from person
)
where (work_hours = 0 and next_work_hours = 1) or (work_hours = 1 and prev_work_hours = 0)
order by first_name, work_date;

如何使用SQL在列中查找具有值序列的行？

4 个答案: