How to join the next date value of the same table - sql

Question

I have a table in SQL with the following fields:
The timestamp field will have all the punches that an employee has in a day.
So having the following data:
I need to create 2 diferent queries.
need to select all the IN timestamps with their corresponding next OUT timestamp
need to select all the OUT timestamps with their corresponding previous IN timestamp
So, in the first query, I should get the following:
In the second query, I should get the following:
Any clue on how to build such queries?
HERE IS THE Fiddle: http://sqlfiddle.com/#!6/a137d/1

Answer 1

I believe this is what you're looking for. These queries should work on most DBMSs.
First
SELECT ea1.employeeid, ea1.timestamp AS instamp, ea2.timestamp AS outstamp
FROM employee_attendance ea1
LEFT JOIN employee_attendance ea2
ON ea2.employeeid=ea1.employeeid
AND ea2.accesscode = 'OUT'
AND ea2.timestamp = (
SELECT MIN(ea3.timestamp)
FROM employee_attendance ea3
WHERE ea3.timestamp > ea1.timestamp
AND ea3.employeeid = ea1.employeeid
)
WHERE ea1.accessCode = 'IN'
AND ea1.employeeid = 4;
Second
SELECT ea1.employeeid, ea1.timestamp AS outstamp, ea2.timestamp AS instamp
FROM employee_attendance ea1
LEFT JOIN employee_attendance ea2
ON ea2.employeeid=ea1.employeeid
AND ea2.accesscode = 'IN'
AND ea2.timestamp = (
SELECT MIN(ea3.timestamp)
FROM employee_attendance ea3
WHERE ea3.timestamp < ea1.timestamp
AND ea3.employeeid = ea1.employeeid
AND ea3.timestamp > ISNULL((
SELECT MAX(ea4.timestamp)
FROM employee_attendance ea4
WHERE ea4.accesscode = 'OUT'
AND ea4.timestamp < ea1.timestamp
AND ea4.employeeid = ea1.employeeid
), '2000-1-1')
)
WHERE ea1.accessCode = 'OUT'
AND ea1.employeeid = 4;

Answer 2

This looks like nice example for usage of LEAD, LAG ANALYTIC functions in SQL 2012.
SELECT * FROM
(
SELECT EMPLOYEEID, TIMESTAMP,
LEAD(timestamp) OVER (ORDER BY TIMESTAMP
) OUTTIMESTAMP, ACCESSCODE
FROM [dbo].[employee_attendance]
WHERE EMPLOYEEID =4
) T
where T.ACCESSCODE ='IN'
second query
SELECT * FROM
(
SELECT EMPLOYEEID, TIMESTAMP,
LAG(timestamp) OVER (ORDER BY TIMESTAMP
) INTIMESTAMP, ACCESSCODE
FROM [dbo].[employee_attendance]
WHERE EMPLOYEEID =4
) T
where T.ACCESSCODE ='OUT'