Create an Attendance view from one column timesheet (SQL Server 2008 R2)

Question

I have this data of attendance from SQL Server that I must split into 2 columns (in and out).

Here is an example:

The Data

And here is the result that I want

Query:

CREATE TABLE [dbo].[Table1]
(
    [ID] [varchar](50) NULL,
    [DATETIME] [datetime] NULL,
    [Flag] [int] NULL
)

INSERT INTO table1 
VALUES ('ID-1', '2019-03-13 09:48:00.000', '2'),
       ('ID-1', '2019-03-13 09:48:00.000', '2'),
       ('ID-1', '2019-03-13 18:11:00.000', '3'),
       ('ID-1', '2019-03-13 18:11:00.000', '3'),
       ('ID-1', '2019-03-14 02:00:00.000', '3'),
       ('ID-1', '2019-03-14 09:54:00.000', '2'),
       ('ID-1', '2019-03-14 09:54:00.000', '2'),
       ('ID-1', '2019-03-14 09:54:00.000', '2'),
       ('ID-1', '2019-03-14 22:00:00.000', '3'),
       ('ID-1', '2019-03-14 22:00:00.000', '3'),
       ('ID-1', '2019-03-14 22:00:00.000', '3'),
       ('ID-1', '2019-03-15 13:55:00.000', '2'),
       ('ID-1', '2019-03-15 13:55:00.000', '2'),
       ('ID-1', '2019-03-15 13:55:00.000', '2'),
       ('ID-1', '2019-03-15 13:55:00.000', '2'),
       ('ID-1', '2019-03-15 13:55:00.000', '2'),
       ('ID-1', '2019-03-15 22:00:00.000', '3'),
       ('ID-1', '2019-03-15 22:00:00.000', '3'),
       ('ID-1', '2019-03-15 22:00:00.000', '3'),
       ('ID-1', '2019-03-15 22:00:00.000', '3')

Note:

1. The flag 2 means IN and 3 means OUT.

2. There can be more than one check in and check out so we must take the first in and last out.

3. There can be overtime so sometimes we must check the check out data from the next day.

How can I do this?

Answer 1

perhaps try a left join from Ins to outs, and find the earliest out time after that in-time.

sample below (untested):

WITH ins
AS ( SELECT *
     FROM   table1
     WHERE  Flag = 2 )
    ,outs
AS ( SELECT *
     FROM   table1
     WHERE  Flag = 3 )
SELECT   i.ID
        ,i.DATETIME InTime
        ,MIN(o.DATETIME) OutTime
FROM     ins i
         LEFT JOIN outs o ON o.ID = i.ID AND o.DATETIME > i.DATETIME -- out must be later than in
GROUP BY i.ID
        ,i.DATETIME
        ,i.Flag;