I have two tables in SQL Server database - users and vacation - sql-server

Question

I want to select all users from the users' table and their data from the vacation table as start vacation date and end date to get their vacation balance and if the user has no vacation taken return 0
Here is my query:
SELECT
dbo.USERINFO.USERID,
dbo.USERINFO.NAME AS إسم_الموظف,
SUM(DATEDIFF(d, dbo.vacation.STARTSDAY, dbo.vacation.ENDSDAY) + 1) AS عددالايام,
dbo.userinfo.balance - (SUM(DATEDIFF(d, dbo.vacation.STARTSDAY, dbo.vacation.ENDSDAY) + 1)) AS الرصيد
FROM
dbo.USERINFO
LEFT JOIN
dbo.Vacation ON dbo.Vacation.UserID = dbo.USERINFO.USERID
WHERE
dbo.USERINFO.DEFAULTDEPTID <> 7
AND dbo.vacation.DATEID = 2
AND year(dbo.vacation.STARTSDAY) = 2020
AND month(dbo.vacation.STARTSDAY) BETWEEN 1
AND 12
GROUP BY
dbo.USERINFO.userid,
dbo.USERINFO.NAME,
dbo.userinfo.balance

Answer 1

You need to move the condition inside the case when statement while calculating the sum
SELECT U.USERID,
U.NAME AS إسم_الموظف,
ISNULL(SUM(CASE WHEN V.DATEID = 2
AND year(V.STARTSDAY) = 2020
THEN DATEDIFF(d, V.STARTSDAY, V.ENDSDAY)
ELSE 0
END), 0) AS عددالايام,
ISNULL(U.balance, 0) - ISNULL(SUM(CASE WHEN V.DATEID = 2
AND year(V.STARTSDAY) = 2020
THEN DATEDIFF(d, V.STARTSDAY, V.ENDSDAY)
ELSE 0
END), 0) AS الرصيد
FROM dbo.USERINFO AS U
LEFT JOIN dbo.Vacation AS V ON V.UserID = U.USERID
WHERE U.DEFAULTDEPTID <> 7
GROUP BY U.userid,
U.NAME,
U.balance
Results:
+--------+------------+-----------+--------+
| USERID | إسم_الموظف | عددالايام | الرصيد |
+--------+------------+-----------+--------+
| 1 | NAME 1 | 8 | 2 |
+--------+------------+-----------+--------+
| 2 | NAME 2 | 6 | 4 |
+--------+------------+-----------+--------+
| 4 | NAME 4 | 0 | 10 |
+--------+------------+-----------+--------+
The script used to generate the dummy data is:
CREATE TABLE USERINFO (USERID int, NAME VARCHAR(20), BALANCE INT, DEFAULTDEPTID INT)
INSERT INTO USERINFO VALUES
(1, 'NAME 1', 10, 5),
(2, 'NAME 2', 10, 4),
(3, 'NAME 3', 10, 7),
(4, 'NAME 4', 10, 5)
CREATE TABLE Vacation (UserID INT, STARTSDAY DATETIME, ENDSDAY DATETIME, DATEID INT)
INSERT INTO Vacation VALUES
(1, '2020-01-12', '2020-01-20', 2),
(1, '2020-01-22', '2020-01-24', 3),
(2, '2020-01-27', '2020-01-31', 2),
(2, '2020-03-27', '2020-03-29', 2),
(7, '2020-03-27', '2020-03-29', 2)
Note that the UserId 3 is retired so it is not included in the result.
Note that vacation with DateId 3 not included when calculating the sum