SQL Database Table Joining to create an IdealTable - sql

Question

I need some helps to join the tables I have currently.
Leave, Overtime And Roster's Date, EmployeeID need to match
Note: ShiftDuration is set to default value = 8.25
Note: Leave and Overtime table will only have entries when an employee applies for leave and overtime.
Employee
EmplyeeeID | Username | Password | GivenName | FamilyName | TeamID | ContactNo | StaffType
------------------------------------------------------------------------------------------
123 123 abc John Snow 1 999 1
1234 1234 abcd Jack Waller 2 223 1
12345 12345 abcde Ali Saw 1 123 1
123456 123456 abcdef Peter Peter 2 223 1
1234567 1234567 abcdeg Bryan Peter 1 333 1
Roster
Duty_ID | EmployeeID | Date | ShiftType | ShiftDuration
--------------------------------------------------------------------
2 123 2018-05-05 1 8.25
4 1234 2018-05-04 1 8.25
5 12345 2018-05-05 1 8.25
7 123456 2018-05-04 1 8.25
8 1234567 2018-05-05 1 8.25
Overtime
OTID | EmployeeID | Date | OT_Duration | OT_Reason
------------------------------------------------------------
2 1234 2018-05-04 2 Cover Duty
Leave
LeaveID | EmployeeID | Date | Duration_Off | Reason
----------------------------------------------------------
3 123 2018-05-05 2 NIL
IdealTable (Via Query)
Date | EmployeeID | GivenName | FamilyName | TeamID | ShiftType | ShiftDuration | Duration_Off | OT_Duration | Total_Hours
---------------------------------------------------------------------------------------------------------------------------------
2018-05-05 123 John Snow 1 1 8.25 2 0 6.25
2018-05-04 1234 Jack Waller 1 1 8.25 0 2 10.25
2018-05-05 12345 Ali Saw 1 1 8.25 0 0 8.25
2018-05-04 123456 Peter Peter 1 1 8.25 0 0 8.25
2018-05-05 1234567 Bryan Peter 1 1 8.25 2 0 8.25
I have 4 tables, they are Employee, Leave, Overtime, Roster
Employee
-EmployeeID (PK)
-Username
-Password
-GivenName
-FamilyName
-TeamID
-ContactNo
-StaffType
Leave
-LeaveID (PK)
-EmployeeID (FK)
-Date
-Duration_Off
-Reason
Overtime
-OTID (PK)
-EmployeeID (FK)
-Date
-OT_Duation
-OT_Reason
Roster
-DutyID (PK)
-EmployeeID (FK)
-Date
-ShiftType
-Shift Duration (Default Value = 8.25)
What I am trying to do is join the data from this 4 tables using Query
Ideal Table
-Date (From Leave, Overtime and Roster Table)
-EmployeeID (Employee Table)
-GivenName (Employee Table)
-FamilyName (Employee Table)
-TeamID (Employee Table)
-ShiftType (Roster Table)
-ShiftDuration (Roster Table)
-Duration_Off (Leave Table)
-OT_Duration (Overtime Table)
-Total_Hours (Calculation from joint table [(ShiftDuration + OT_Duration) - Duration_Off]
My database diagram design Do ignore the TimeData table as I initially wanted to use the TimeData table to achieve the IdealTable
My current query
USE [SMRT Dashboard]
GO
;With Dates
AS
(
SELECT [Date] FROM dbo.Roster
UNION
SELECT [Date] FROM dbo.Leave
UNION
SELECT [Date] FROM dbo.Overtime
),
Work_Matrix
AS
(
SELECT EmployeeID,[Date],ShiftType,ShiftDuration,CAST(NULL AS Decimal(30,2)) AS Duration_Off,CAST(NULL AS Decimal(30,2)) AS OT_Duration
FROM dbo.Roster
UNION ALL
SELECT EmployeeID,[Date], NULL, NULL,Duration_Off
FROM dbo.Leave
UNION ALL
SELECT EmployeeID,[Date],NULL,NULL,NULL,OT_Duration
FROM dbo.Overtime
)
SELECT d.[Date],
e.EmployeeID,
e.GivenName,
e.FamilyName,
e.TeamID,
w.ShiftType,
w.ShiftDuration,
w.Duration_Off,
w.OT_Duration,
w.Total_Hours
FROM Dates d
INNER JOIN
(
SELECT EmployeeID,
[Date],
MAX(ShiftType) AS ShiftType,
SUM(ShiftDuration) AS ShiftDuration,
SUM(Duration_Off) AS Duration_Off,
SUM(OT_Duration) AS OT_Duration,
SUM(ShiftDuration) + SUM(OT_Duration) - SUM(Duration_Off) AS Total_Hours
FROM Work_Matrix
GROUP BY EmployeeID,
[Date]
)w
ON d.[Date] = w.[Date]
JOIN dbo.Employee e
ON e.EmployeeID = w.EmployeeID
Current Errors:
Msg 205, Level 16, State 1, Line 4
All queries combined using a UNION, INTERSECT or EXCEPT operator must have an equal number of expressions in their target lists.

Answer 1

I have not tested this but you may now check this. Hope your problem will be solved.
SELECT
a.EmployeeID,
a.GivenName,
a.FamilyName,
a.TeamID,
d.ShiftType,
d.ShiftDuration,
b.Duration_Off,
c.OT_Duration,
b.Date,
(d.ShiftDuration + c.OT_Duration) - b.Duration_Off as Total_Hours
FROM Employee a
INNER JOIN Roster d ON a.EmployeeID = d.EmployeeID
LEFT JOIN Leave b ON a.EmployeeID = b.EmployeeID
LEFT JOIN Overtime c ON a.EmployeeID = c.EmployeeID
I assume Date is same from all three tables (Leave, Overtime and Roster Table)

Answer 2

Try this query :
select
l.Date,
o.Date,
r.Date,
e.EmployeeID,
e.GivenName,
e.FamilyName,
e.TeamID,
r.ShiftType,
r.ShiftDuration,
l.Duration_Off,
o.OT_Duration,
((r.ShiftDuration+o.OT_Duration)-l.Duration_Off) as Total_Hours
FROM Employee e
INNER JOIN Leave l ON e.EmployeeID = l.EmployeeID
INNER JOIN Overtime o ON e.EmployeeID = o.EmployeeID
INNER JOIN Roster r ON r.EmployeeID = r.EmployeeID;

Answer 3

Try this Query ! You will get the correct output .
SELECT
e.EmployeeID AS 'Emp ID',
e.GivenName AS 'Emp Name',
l.Date AS Date,
e.FamilyName AS 'Family Name',
e.TeamID AS 'Team ID',
r.ShiftType AS 'Shift Type',
r.ShiftDuration AS 'Shift Duration',
l.Duration_Off AS 'Duration Off',
o.OT_Duration AS 'OT Duration',
(r.ShiftDuration + o.OT_Duration) - l.Duration_Off as 'Total Hours'
FROM
Employee e,
Leave l,
Overtime o,
Roster r
WHERE
e.EmployeeID = l.EmployeeID
AND
e.EmployeeID = o.EmployeeID
AND
e.EmployeeID = r.EmployeeID

Answer 4

I think the issue here is that an employee may have leave, may have overtime, or neither. By using INNER JOIN, you're filtering down the set of employees to ones that have Leave, and on a Roster, and have Overtime.
I created a SqlFiddle with the data you present (see here) that should get you closer.
SELECT
COALESCE(r.Date, o.Date, l.Date) as Date,
e.EmployeeID,
e.GivenName,
e.FamilyName,
e.TeamID,
r.ShiftType,
r.ShiftDuration,
IFNULL(l.Duration_Off, 0) as Duration_Off,
IFNULL(o.OT_Duration, 0) as OT_Duration,
r.ShiftDuration + IFNULL(o.OT_Duration, 0) - IFNULL(l.Duration_Off, 0) as Total_Hours
FROM Employee e
INNER JOIN Roster r on
e.EmployeeID = r.EmployeeID
LEFT JOIN Overtime o on
e.EmployeeID = o.EmployeeID
LEFT JOIN `Leave` l on
e.EmployeeID = l.EmployeeID
There's a few cavaets that this query won't solve:
If an employee has multiple leave entries or multiple overtime entries, the person will be listed N times. You can potentially use a GROUP BY statement to deal with this
The sample data in your question doesn't reconcile correctly. For example, Employe 1234 has a shift on 5/4/2018 and OT on 5/5/2018 but gets 10.25 on 5/4/2018.
If you use TimeData, this becomes a lot easier (assuming one record per date per employee):
SELECT
COALESCE(r.Date, o.Date, l.Date) as Date,
e.EmployeeID,
e.GivenName,
e.FamilyName,
e.TeamID,
r.ShiftType,
IFNULL(r.ShiftDuration, 0) as ShiftDuration,
IFNULL(l.Duration_Off, 0) as Duration_Off,
IFNULL(o.OT_Duration, 0) as OT_Duration,
IFNULL(r.ShiftDuration, 0) + IFNULL(o.OT_Duration, 0) - IFNULL(l.Duration_Off, 0) as Total_Hours
from TimeData t
INNER JOIN Employee e on
t.EmployeeID = e.EmployeeID
LEFT JOIN Roster r on
t.Duty_ID = r.Duty_ID
LEFT JOIN Overtime o on
t.OTID = o.OTID
LEFT JOIN `Leave` l on
t.LeaveID = l.LeaveID
Example SqlFiddle can be found here