Question

Im using Ms SQL database,
My table looks,

SrNo  Emp_ID   Date          Time 
------------------------------------
  1    25     03-Sep-12    9:35:35 AM  
  2    25     03-Sep-12   10:31:32 AM 
  3    25     03-Sep-12   10:34:13 AM 
  4    25     03-Sep-12   11:05:08 AM 
  5    25     03-Sep-12   11:08:39 AM 
  6    25     04-Sep-12   09.05.40 AM     

The expected output is

 SrNo  Emp_ID   Date          Time     Type 
---------------------------------------------
  1    25     03-Sep-12    9:35:35 AM  IN
  2    25     03-Sep-12   10:31:32 AM  OUT
  3    25     03-Sep-12   10:34:13 AM  IN
  4    25     03-Sep-12   11:05:08 AM  OUT
  5    25     03-Sep-12   11:08:39 AM  IN
  6    25     04-Sep-12   09.05.40 AM  IN

For an employee, type “in” and “out” has to be added simultaneously for particular date. For the next date or next /same employee, type has to start with “IN”. Can any 1 help me in writing the sql query.

Answer 1

You can achieve this using an additional column

ROW_NUMBER() OVER (PARTITION BY Emp_ID, Date ORDER BY Time) AS RN

then checking modulus 2 on it, if remainder is 1, it’s an IN, if it’s 0 it’s an OUT, based on your requirements.

More specifically

CASE WHEN 
  ROW_NUMBER() OVER (PARTITION BY Emp_ID, Date ORDER BY Time) % 2 = 1 
     THEN 'IN' 
     ELSE 'OUT' 
  END AS [Type]