Merge two consecutive rows into a column

Provided mytable contains only valid pairs of in / out events

select EmployeeCode, 
  max(case EntryType when 'IN' then TIME end ) IN_TIME,
  max(case EntryType when 'OUT' then TIME end ) OUT_TIME
from ( 
   select EmployeeCode, EntryType, TIME,
     row_number() over(partition by EmployeeCode, EntryType order by TIME) rn
   from mytable
   )t
group by EmployeeCode, rn
order by EmployeeCode, rn

Otherwise a kind of clean-up is required first.

One solution that may work is using inner joins .. as you may have multiple In & Out records.

Select A.EmployeeCode,
       Min(TIME) IN_TIME,
       (Select Max(A2.TIME) From Attendance A2 Where A2.EmployeeCode = A.EmployeeCode And A2.EntryType = 'OUT') OUT_TIME
From Attendance  A
Where A.EntryType = 'IN'
Group By A.EmployeeCode

So, The main query get the max Out time for each employee & the inner query get the min In time. That solution supposes that at least each employee has one IN record

Assuming there are always pairs of IN/OUT, you can use LEAD to get the next value

select
  EmployeeCode, 
  TIME as IN_TIME,
  nextTime AS OUT_TIME
from ( 
   select *,
     lead(case EntryType when 'OUT' then TIME end) over (partition by EmployeeCode order by TIME) nextTime
   from mytable
) t
where EntryType = 'IN';