Get all dates between provided dates - sql

Question

I have this table and sample data. I want to get the entire month's or specific dates attendance and information like hours he worked or days he was absent.
CREATE TABLE Attendance
(
[EmpCode] int,
[TimeIn] datetime,
[TimeOut] datetime
)
INSERT INTO Attendance VALUES (12, '2018-08-01 09:00:00', '2018-08-01 17:36:00');
INSERT INTO Attendance VALUES (12, '2018-08-02 09:00:00', '2018-08-02 18:10:00');
INSERT INTO Attendance VALUES (12, '2018-08-03 09:25:00', '2018-08-03 16:56:00');
INSERT INTO Attendance VALUES (12, '2018-08-04 09:13:00', '2018-08-05 18:09:00');
INSERT INTO Attendance VALUES (12, '2018-08-06 09:00:00', '2018-08-07 18:15:00');
INSERT INTO Attendance VALUES (12, '2018-08-07 09:27:00', '2018-08-08 17:36:00');
INSERT INTO Attendance VALUES (12, '2018-08-08 09:35:00', '2018-08-09 17:21:00');
INSERT INTO Attendance VALUES (12, '2018-08-10 09:00:00', '2018-08-10 17:45:00');
INSERT INTO Attendance VALUES (12, '2018-08-11 09:50:00', '2018-08-11 17:31:00');
INSERT INTO Attendance VALUES (12, '2018-08-13 09:23:00', '2018-08-13 17:19:00');
INSERT INTO Attendance VALUES (12, '2018-08-15 09:21:00', '2018-08-15 17:36:00');
INSERT INTO Attendance VALUES (12, '2018-08-16 09:00:00', '2018-08-16 17:09:00');
INSERT INTO Attendance VALUES (12, '2018-08-17 09:34:00', '2018-08-17 17:29:00');
INSERT INTO Attendance VALUES (12, '2018-08-18 09:00:00', '2018-08-18 17:10:00');
INSERT INTO Attendance VALUES (12, '2018-08-20 09:34:00', '2018-08-20 17:12:00');
INSERT INTO Attendance VALUES (12, '2018-08-21 09:20:00', '2018-08-21 17:15:00');
INSERT INTO Attendance VALUES (12, '2018-08-22 09:12:00', '2018-08-22 17:19:00');
INSERT INTO Attendance VALUES (12, '2018-08-23 09:05:00', '2018-08-23 17:21:00');
INSERT INTO Attendance VALUES (12, '2018-08-24 09:07:00', '2018-08-24 17:09:00');
INSERT INTO Attendance VALUES (12, '2018-08-25 09:12:00', '2018-08-25 17:05:00');
INSERT INTO Attendance VALUES (12, '2018-08-27 09:21:00', '2018-08-27 17:46:00');
INSERT INTO Attendance VALUES (12, '2018-08-28 09:17:00', '2018-08-28 17:12:00');
INSERT INTO Attendance VALUES (12, '2018-08-29 09:00:00', '2018-08-29 17:36:00');
INSERT INTO Attendance VALUES (12, '2018-08-30 09:12:00', '2018-08-30 17:24:00');
I have a query that tells how many hours employee have worked, but it is only showing days on which data was present in table. I want to show all dates between provided dates and in case there is no data it should NULL in columns.
Here is the query:
SELECT
[EmpCode],
FirstIN = CAST(MIN([TimeIn]) AS TIME),
LastOUT = CAST(MAX([TimeOut]) AS TIME),
CONVERT(VARCHAR(6), Datediff(second, CAST(MIN([TimeIn]) AS TIME), CAST(MAX([TimeOut]) AS TIME))/3600)
+ ':'
+ RIGHT('0' + CONVERT(VARCHAR(2), (Datediff(second, CAST(MIN([TimeIn]) AS TIME), CAST(MAX([TimeOut]) AS TIME)) % 3600) / 60), 2)
+ ':'
+ RIGHT('0' + CONVERT(VARCHAR(2), Datediff(second, CAST(MIN([TimeIn]) AS TIME), CAST(MAX([TimeOut]) AS TIME)) % 60) , 2 ) AS HoursSpent,
CAST(COALESCE(TimeIn, TimeOut) AS DATE) [Date]
FROM Attendance
WHERE CAST(COALESCE(TimeIn, TimeOut) AS DATE) BETWEEN '2018-08-01' AND '2018-08-25'
GROUP BY EmpCode, TimeIn, TimeOut

Answer 1

For that you need to use recursive way to generate possible dates :
with t as (
select '2018-08-01' as startdt
union all
select dateadd(day, 1, startdt)
from t
where startdt < '2018-08-25'
)
select . . .
from t left join
Attendance at
on cast(coalesce(at.TimeIn, at.TimeOut) as date) = t.startdt;
Just make sure to use date from t instead of Attendance table in SELECT statement.
Note : If you have a large no of date period, then don't forgot to use Query hint OPTION (MAXRECURSION 0), By defalut it has 100 recursion levels.

Answer 2

You May Try Recursive CTE to populate the Dates and Then Join With that to Get the Interval
DECLARE #From DATETIME = '2018-08-01' ,#To DATETIME= '2018-08-25'
;WITH CTE
AS
(
SELECT
[EmpCode] EmpId,
MyDate = #From
FROM Attendance A
UNION ALL
SELECT
EmpId,
MyDate = DATEADD(DAY,1,MyDate)
FROM CTE
WHERE MyDate < #To
)
SELECT
[EmpCode] = CTE.EmpId,
CTE.MyDate,
FirstIN = CAST(MIN([TimeIn]) AS TIME),
LastOUT = CAST(MAX([TimeOut]) AS TIME),
CONVERT(VARCHAR(6), Datediff(second, CAST(MIN([TimeIn]) AS TIME), CAST(MAX([TimeOut]) AS TIME))/3600)
+ ':'
+ RIGHT('0' + CONVERT(VARCHAR(2), (Datediff(second, CAST(MIN([TimeIn]) AS TIME), CAST(MAX([TimeOut]) AS TIME)) % 3600) / 60), 2)
+ ':'
+ RIGHT('0' + CONVERT(VARCHAR(2), Datediff(second, CAST(MIN([TimeIn]) AS TIME), CAST(MAX([TimeOut]) AS TIME)) % 60) , 2 )
AS HoursSpent,
CAST(CTE.MyDate AS DATE) [Date]
FROM CTE
LEFT JOIN Attendance A
ON A.EmpCode = CTE.EmpId
AND CAST(CTE.MyDate AS DATE) = CAST(COALESCE(TimeIn, TimeOut) AS DATE)
GROUP BY CTE.EmpId, TimeIn, TimeOut,CTE.MyDate
ORDER BY 6

Answer 3

A different method, using a Tally Table. The advantage here is that an rCTE is a form of RBAR. The idea of a Tally table isn't as obvious, but is quicker, and also, won't need the OPTION (MAXRECURSION 0) added if you have more than 100 days. in fact, this example handles up to 10,000 days, which shuold be more than enough:
DECLARE #EmpCode int = 12;
WITH N AS(
SELECT N
FROM (VALUES(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL)) N(N)),
Tally AS(
SELECT ROW_NUMBER() OVER (ORDER BY (SELECT NULL)) -1 AS I
FROM N N1 --10
CROSS JOIN N N2 --100
CROSS JOIN N N3 --1000
CROSS JOIN N N4 --10000
),
Dates AS(
SELECT DATEADD(DAY, T.I, TT.MinTimeIn) AS CalendarDate,
#EmpCode AS EmpCode
FROM Tally T
CROSS APPLY (SELECT MIN(CONVERT(date,TimeIn)) AS MinTimeIn,
MAX(CONVERT(date,TimeOut)) AS MaxTimeOut
FROM Attendance
WHERE EmpCode = #EmpCode) TT
WHERE DATEADD(DAY, T.I, TT.MinTimeIn) <= CONVERT(date, TT.MaxTimeOut))
SELECT CalendarDate
EmpCode,
TimeIn,
TimeOut
FROM Dates D
LEFT JOIN Attendance A ON D.CalendarDate = CONVERT(date,A.TimeIn)
AND D.EmpCode = A.EmpCode;