Question

I am developing a web application for my company. This application provides the users with quizzes. Now, I need to develop a powerful and meaningful dashboard to the management. The dashboard must show show % participation = (sum of all quizzes taken by each employee) / (total number of employees * total number of quizzes)

The question is: I have the following database design:

Employee Table: Username, Name, Job, DivisionID

Division Table: DivisionID, DivisionName

Quiz Table: QuizID, Title, Description

UserQuiz Table: UserQuizID, Score, DateTimeComplete, QuizID, Username

NOTE: The first attribute in each table is the primary key.

The SQL Query that I am using (but I am not sure about it) to show the percentage completion is:

DECLARE @LastDayOfPrevMonth DATETIME, @FirstDayOfThreeMonthsBefore DATETIME

SET @FirstDayOfThreeMonthsBefore = DATEADD(MONTH, -2, DATEADD(MONTH, DATEDIFF(MONTH, 0, CURRENT_TIMESTAMP), 0))
SET @LastDayOfPrevMonth = GETDATE()

;WITH MonthCTE AS
(
SELECT DATENAME(MONTH, DATEADD(MONTH, -2, CURRENT_TIMESTAMP)) + '-' + DATENAME(YEAR, DATEADD(MONTH, -2, CURRENT_TIMESTAMP)) AS MonthYear
UNION ALL 
SELECT DATENAME(MONTH, DATEADD(MONTH, -1, CURRENT_TIMESTAMP)) + '-' + DATENAME(YEAR, DATEADD(MONTH, -1, CURRENT_TIMESTAMP))
UNION ALL
SELECT DATENAME(MONTH, DATEADD(MONTH, 0, CURRENT_TIMESTAMP)) + '-' + DATENAME(YEAR, DATEADD(MONTH, 0, CURRENT_TIMESTAMP))
)

    SELECT  Divisions.DivisionName
,       [Percentage Participation] = CAST([Total Number of Quizzes Taken]
        * 100.00 / [Total Number of Quizzes] AS DECIMAL(18, 2))
,       [Total Number of Quizzes Taken]
,       [Total Number of Quizzes]
,     [Total Number of Employees]
,       MonthYear [Month]
,     LEFT([MonthYear],3) + RIGHT([MonthYear], LEN([MonthYear]) - CHARINDEX('-',[MonthYear]) + 1) FirstThreeLettersOfMonth

FROM    dbo.Divisions Divisions CROSS JOIN 
    (SELECT ISNULL(NULLIF(COUNT(*),0),1) [Total Number of Quizzes]FROM [dbo].[Quiz] ) Quiz
    OUTER APPLY (SELECT COUNT(*) AS [Total Number of Employees] 
               FROM [dbo].[employee]
               WHERE employee.DivisionCode = Divisions.SapCode
               ) Employee 
    OUTER APPLY (
                 SELECT    ISNULL([Total Number of Quizzes Taken],0) [Total Number of Quizzes Taken],
                           MonthCTE.MonthYear FROM
                 (SELECT   COUNT(DISTINCT UserQuiz.QuizID) AS [Total Number of Quizzes Taken],
                            DATENAME(MONTH, UserQuiz.DateTimeComplete) + '-' + DATENAME(YEAR, UserQuiz.DateTimeComplete) MonthYear
                  FROM      UserQuiz UserQuiz
                            INNER JOIN employee employee 
                            ON UserQuiz.Username = employee.Username
                  WHERE     employee.DivisionCode = Divisions.SapCode 
                  AND       UserQuiz.DateTimeComplete BETWEEN @FirstDayOfThreeMonthsBefore AND @LastDayOfPrevMonth
                  GROUP BY DATENAME(MONTH, UserQuiz.DateTimeComplete), DATENAME(YEAR, UserQuiz.DateTimeComplete)
                  )Quiz
                  RIGHT JOIN MonthCTE ON Quiz.MonthYear = MonthCTE.MonthYear
                ) QuizMonthOutput

What I want now is just showing the Percent Completion for the LAST MONTH only.

I think my problem now is just with finding the total number of employees in each division to add it to this part of the above query:

SELECT  Divisions.DivisionShortcut
,       [Percent Completion] = CAST([Sum of all Quizzes Taken by each Employee]
        * 100.00 / ([Total Number of Employees]*[Total Number of Quizzes]) AS DECIMAL(18, 2))

So how to do that?

Sample of desired output:

The calculation should be: The percent completion should be calculated as mentioned above which is equal to (sum of all quizzes taken by each employee)/(total number of employees * total number of quizzes). For example, in Division A, if there are two employees Emp1 and Emp2. Each month, there are four quizzes. Emp1 took Quiz#1 and Quiz#2 and Emp2 took Quiz#4. The Percent Completion should be = ((Emp1 * 2 Quizzes) + (Emp2 * 1 Quiz)) / (total number of employees * total number of quizzes)

Percent Completion = (2 + 1) / (2*4) = 2 / 8 = 0.25

Answer 1

Try this:

DROP TABLE #Employee
DROP TABLE #Division
DROP TABLE #Quiz
DROP TABLE #UserQuiz

CREATE TABLE #Employee(
  Username  CHAR(10), 
  Name  VARCHAR(20),
  Job       VARCHAR(20),
  DivisionID    INT
)
INSERT INTO #Employee(Username, Name, Job, DivisionID) VALUES
('Me', 'Me', 'job1', 1),
('Myself', 'Myself', 'job2', 1),
('Andy', 'Andy', 'job3', 1),
('Ai', 'Ai', 'job4', 2)

CREATE TABLE #Division(
  DivisionID    INT, 
  DivisionName  VARCHAR(20)
)
INSERT INTO #Division(DivisionID, DivisionName) VALUES
(1, 'Div1'),
(2, 'Div2')

CREATE TABLE #Quiz(
  QuizID    INT, 
  Title VARCHAR(20), 
  Description   VARCHAR(20)
)
INSERT INTO #Quiz(QuizID, Title, Description) VALUES
(1, 'Quiz1', 'Quiz1'),
(2, 'Quiz2', 'Quiz2'),
(3, 'Quiz3', 'Quiz3'),
(4, 'Quiz4', 'Quiz4'),
(5, 'Quiz5', 'Quiz5'),
(6, 'Quiz6', 'Quiz6'),
(7, 'Quiz7', 'Quiz7'),
(8, 'Quiz8', 'Quiz8')

CREATE TABLE #UserQuiz(
  UserQuizID    INT, 
  Score INT, 
  DateTimeComplete  DATETIME, 
  QuizID    INT, 
  Username  CHAR(10), 
)
INSERT INTO #UserQuiz(UserQuizID, Score, DateTimeComplete, QuizID, Username) VALUES
(1, 10, '20000101', 1, 'Me'),
(2, 0,  '20000101', 1, 'Myself'),
(3, 10, '20120210', 5, 'Me'),
(4, 10, '20120210', 6, 'Myself'),
(5, 10, '20120210', 7, 'Andy'),
(6, 10, '20120101', 5, 'Ai')

DECLARE @LastDayOfPrevMonth DATETIME, @FirstDayOfPrevMonth DATETIME

SET @FirstDayOfPrevMonth = DATEADD(dd, -DAY(DATEADD(mm, 1, GetDate()) - 1), DATEADD(mm, -1, GetDate()))
SET @LastDayOfPrevMonth = DATEADD(dd, -DAY(DATEADD(m, 1, GetDate())), DATEADD(m, 0, GetDate()))

;WITH LastMontQuizes AS
(SELECT distinct QuizID
FROM #UserQuiz
WHERE DateTimeComplete BETWEEN @FirstDayOfPrevMonth AND @LastDayOfPrevMonth
),
NumberOfQuizes AS
(SELECT COUNT(*) as NumberOfQuizes
FROM LastMontQuizes
),
NrOfQuizesPerDivision AS
(SELECT COUNT(*) as NrOfQuizesPerDivision, #Division.DivisionID
FROM #Division
  INNER JOIN #Employee ON
    #Division.DivisionID = #Employee.DivisionID
  INNER JOIN #UserQuiz ON
    #Employee.Username = #UserQuiz.Username
  INNER JOIN LastMontQuizes ON
    #UserQuiz.QuizID = LastMontQuizes.QuizID
GROUP BY #Division.DivisionID
),
NrOfEmployeesPerDivision AS
(SELECT COUNT(*) as NrOfEmployeesPerDivision, #Division.DivisionID
FROM #Division
  INNER JOIN #Employee ON
    #Division.DivisionID = #Employee.DivisionID
GROUP BY #Division.DivisionID
)
SELECT #Division.DivisionName,
  NrOfQuizesPerDivision.DivisionID, 
  NrOfQuizesPerDivision.NrOfQuizesPerDivision * 100.0 / (NrOfEmployeesPerDivision.NrOfEmployeesPerDivision + NumberOfQuizes.NumberOfQuizes) AS Percentage,
  NrOfQuizesPerDivision.NrOfQuizesPerDivision,
  NrOfEmployeesPerDivision.NrOfEmployeesPerDivision,
  NumberOfQuizes.NumberOfQuizes
FROM NrOfQuizesPerDivision
  INNER JOIN NrOfEmployeesPerDivision ON
    NrOfQuizesPerDivision.DivisionID = NrOfEmployeesPerDivision.DivisionID
  INNER JOIN #Division ON
    NrOfQuizesPerDivision.DivisionID = #Division.DivisionID
  CROSS JOIN NumberOfQuizes