Shift manipulation in SQL to get counts - sql

Question

I have attendance in following table called Attendance
EID is employee ID and in shift column, D denotes a Day shift and N denotes a Night shift.
Now I'm trying to get following data pertaining to each employee.
No of Day shifts - count of D,
No of Night shifts - count of N,
No of Days worked - no of days an employee has worked either shift or both shifts (Even an employee worked both Day and Night on the same day its taken as one day.)
I can get all three information in three different results as follows...
WITH CTE (EID, in_time, shift) AS
(
SELECT EID, in_time, shift FROM Attendance
WHERE (in_time BETWEEN CONVERT(DATETIME, '2014-01-07 00:00:00', 102) AND CONVERT(DATETIME, '2014-07-31 00:00:00', 102)) AND PID = 'A002'
)
SELECT EID, COUNT(*) AS DayTotal
FROM CTE
WHERE (shift = 'D')
GROUP BY EID
SELECT EID, COUNT(*) AS NightTotal
FROM Attendance
WHERE (shift = 'N')
GROUP BY EID
;
WITH CTE2 (EID, in_time, shift) AS
(
SELECT EID, in_time, shift FROM Attendance
WHERE (in_time BETWEEN CONVERT(DATETIME, '2014-01-07 00:00:00', 102) AND CONVERT(DATETIME, '2014-07-31 00:00:00', 102)) AND PID = 'A002'
)
SELECT EID, COUNT ( DISTINCT CONVERT (DATE, in_time)) AS [Days]
FROM CTE2
WHERE (shift = 'D' OR shift = 'N')
GROUP BY EID
But I want to have this in single result (table). So I tried following query but it's not giving the intended output.
WITH CTE (EID, in_time, shift) AS
(
SELECT EID, in_time, shift FROM Attendance
WHERE (in_time BETWEEN CONVERT(DATETIME, '2014-01-07 00:00:00', 102) AND CONVERT(DATETIME, '2014-07-31 00:00:00', 102)) AND PID = 'A002'
)
SELECT EID,
CASE WHEN Shift = 'D' THEN COUNT(Shift) END AS [Day],
CASE WHEN Shift = 'N' THEN COUNT(Shift) END AS [Night],
COUNT ( DISTINCT CONVERT (DATE, in_time)) AS [Days]
FROM CTE
GROUP BY EID, shift
Could you please let me know a way to do this?
The intended result

Answer 1

I think you can get what you want using conditional aggregation:
SELECT EID,
sum(case when shift = 'd' then 1 else 0 end) as dayshifts,
sum(case when shift = 'n' then 1 else 0 end) as nightshifts,
count(*) as total
FROM Attendance a
WHERE (in_time BETWEEN CONVERT(DATETIME, '2014-01-07 00:00:00', 102) AND
CONVERT(DATETIME, '2014-07-31 00:00:00', 102)) AND
PID = 'A002';
EDIT:
If you want counts of distinct dates for the total, then use count(distinct):
SELECT EID,
sum(case when shift = 'd' then 1 else 0 end) as dayshifts,
sum(case when shift = 'n' then 1 else 0 end) as nightshifts,
count(distinct case when shift in ('d', 'n') then cast(in_time as date) end) as total
FROM Attendance a
WHERE (in_time BETWEEN CONVERT(DATETIME, '2014-01-07 00:00:00', 102) AND
CONVERT(DATETIME, '2014-07-31 00:00:00', 102)) AND
PID = 'A002';

Answer 2

WITH cte (eid, in_time, shift)
AS (SELECT eid,
in_time,
shift
FROM attendance
WHERE ( in_time BETWEEN CONVERT(DATETIME, '2014-01-07 00:00:00', 102)
AND
CONVERT(DATETIME,
'2014-07-31 00:00:00',
102
) )
AND pid = 'A002')
SELECT eid,
Sum(CASE
WHEN shift = 'D' THEN 1
ELSE 0
END) AS DayTotal,
Sum(CASE
WHEN shift = 'N' THEN 1
ELSE 0
END) AS NightTotal,
Count (DISTINCT CONVERT (DATE, in_time)) AS Days
FROM cte
GROUP BY eid

Answer 3

#Chathuranga, Since Day and Night Shifts of a day should be counted as one, Please let me know if the below solution works for you.
DECLARE #Attendance TABLE (EID INT,
PID CHAR(4),
In_Time DATETIME,
Out_Time DATETIME,
Shift CHAR(1))
INSERT INTO #Attendance
VALUES
('100', 'A001', '2014-07-01 07:00:00.000', '2014-07-01 19:30:00.000', 'D'),
('102', 'A001', '2014-07-01 19:30:00.000', '2014-07-02 07:00:00.000', 'N'),
('100', 'A001', '2014-07-01 19:30:00.000', '2014-07-02 07:00:00.000', 'N'),
('104', 'A001', '2014-07-02 07:00:00.000', '2014-07-02 19:30:00.000', 'D'),
('100', 'A001', '2014-07-03 19:30:00.000', '2014-07-04 07:00:00.000', 'N'),
('102', 'A001', '2014-07-03 19:30:00.000', '2014-07-04 07:00:00.000', 'N'),
('104', 'A001', '2014-07-03 07:00:00.000', '2014-07-03 19:30:15.000', 'D'),
('102', 'A001', '2014-07-04 07:00:00.000', '2014-07-04 19:30:00.000', 'D'),
('100', 'A001', '2014-07-04 07:00:00.000', '2014-07-04 19:30:10.000', 'D')
SELECT EID,
SUM(CASE
WHEN Shift = 'D' THEN 1
ELSE 0
END) AS DayShift,
SUM(CASE
WHEN Shift = 'N' THEN 1
ELSE 0
END) AS NightShift,
COUNT(DISTINCT CAST(In_Time AS DATE)) AS DayTotal
FROM #Attendance
GROUP BY EID