I am a new web developer and I am developing a simple training management system which provides the users with quizzes. The system developed using ASP.NET and MS SQLServer. Now, I need to come up with a query that shows the percentage of participation of each division in all the offered safety quizzes (which means quizzes with IsSent = true).
I have the following database design:
Employee Table: Username, Name, DivisionCode
Divisions Table: SapCode, Divison
Quiz Table: QuizID, Title, Description, IsSent
UserQuiz: UserQuizID, QuizID, DateTimeComplete, Username
(DivisionCode is a foreign key to the SapCode. IsSent is a flag to indicate to the quizzes that have been offered and sent to the users to participate in them.)
For example, If I have four divisions; A, B, C and D, and I have around 23 quizzes have been sent to the employees in those divisions. Since each division has a specific percentage of participation in each quiz. My query should show the overall percentage of participation in all offered quizzes for each division. So the result should not be broken down with respect to each quiz.
The desired result that I am looking for it:
Division ************************* Overall Percentage
A ******************************** 80
B ******************************** 60
C ******************************** 50
And the overall percentage is the total of all percent completion of each division in each quiz. For instance, the percent completion for division A in Quiz#1 = 40%, and in Quiz#2 = 60% and in Quiz#3 = 90%, the overall percentage that should be shown by this query is the total of all the of them divided by the total number of sent quizzes (which is 3). I hope I am clear and the concept is obvious.
So how to do that?
And here's the schema of the database with its data:
USE [Test]
GO
/****** Object: Table [dbo].[Divisions] Script Date: 08/03/2012 19:36:09 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
SET ANSI_PADDING ON
GO
CREATE TABLE [dbo].[Divisions](
[SapCode] [nvarchar](50) NOT NULL,
[Division] [varchar](50) NOT NULL,
CONSTRAINT [PK_Divisions] PRIMARY KEY CLUSTERED
(
[SapCode] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
GO
SET ANSI_PADDING OFF
GO
INSERT [dbo].[Divisions] ([SapCode], [Division]) VALUES (N'1', N'A')
INSERT [dbo].[Divisions] ([SapCode], [Division]) VALUES (N'2', N'B')
INSERT [dbo].[Divisions] ([SapCode], [Division]) VALUES (N'3', N'C')
/****** Object: Table [dbo].[Quiz] Script Date: 08/03/2012 19:36:09 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
SET ANSI_PADDING ON
GO
CREATE TABLE [dbo].[Quiz](
[QuizID] [int] IDENTITY(1,1) NOT NULL,
[Title] [varchar](50) NOT NULL,
[Description] [varchar](50) NOT NULL,
[IsSent] [bit] NOT NULL,
CONSTRAINT [PK_Quiz] PRIMARY KEY CLUSTERED
(
[QuizID] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
GO
SET ANSI_PADDING OFF
GO
SET IDENTITY_INSERT [dbo].[Quiz] ON
INSERT [dbo].[Quiz] ([QuizID], [Title], [Description], [IsSent]) VALUES (1, N'Quiz I', N'Test', 1)
INSERT [dbo].[Quiz] ([QuizID], [Title], [Description], [IsSent]) VALUES (2, N'Quiz II', N'Test test', 1)
INSERT [dbo].[Quiz] ([QuizID], [Title], [Description], [IsSent]) VALUES (3, N'Quiz III', N'TEST TEST', 0)
SET IDENTITY_INSERT [dbo].[Quiz] OFF
/****** Object: Table [dbo].[Employee] Script Date: 08/03/2012 19:36:09 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
SET ANSI_PADDING ON
GO
CREATE TABLE [dbo].[Employee](
[Usename] [nvarchar](50) NOT NULL,
[Name] [varchar](50) NOT NULL,
[DivisionCode] [nvarchar](50) NOT NULL,
CONSTRAINT [PK_Employee] PRIMARY KEY CLUSTERED
(
[Usename] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
GO
SET ANSI_PADDING OFF
GO
INSERT [dbo].[Employee] ([Usename], [Name], [DivisionCode]) VALUES (N'John12', N'John A', N'1')
INSERT [dbo].[Employee] ([Usename], [Name], [DivisionCode]) VALUES (N'John13', N'John B', N'1')
INSERT [dbo].[Employee] ([Usename], [Name], [DivisionCode]) VALUES (N'John15', N'John C', N'3')
INSERT [dbo].[Employee] ([Usename], [Name], [DivisionCode]) VALUES (N'Maria12', N'Maria A', N'3')
INSERT [dbo].[Employee] ([Usename], [Name], [DivisionCode]) VALUES (N'Rony14', N'Rony A', N'2')
INSERT [dbo].[Employee] ([Usename], [Name], [DivisionCode]) VALUES (N'Tid52', N'Tid A', N'3')
INSERT [dbo].[Employee] ([Usename], [Name], [DivisionCode]) VALUES (N'Tim12', N'Tim A', N'1')
INSERT [dbo].[Employee] ([Usename], [Name], [DivisionCode]) VALUES (N'Tim15', N'Tim B', N'2')
/****** Object: Table [dbo].[UserQuiz] Script Date: 08/03/2012 19:36:09 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE TABLE [dbo].[UserQuiz](
[UserQuizID] [int] IDENTITY(1,1) NOT NULL,
[QuizID] [int] NOT NULL,
[DateTimeComplete] [datetime] NOT NULL,
[Score] [float] NOT NULL,
[Username] [nvarchar](50) NOT NULL,
CONSTRAINT [PK_UserQuiz] PRIMARY KEY CLUSTERED
(
[UserQuizID] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
GO
SET IDENTITY_INSERT [dbo].[UserQuiz] ON
INSERT [dbo].[UserQuiz] ([UserQuizID], [QuizID], [DateTimeComplete], [Score], [Username]) VALUES (1, 1, CAST(0x0000A07900000000 AS DateTime), 100, N'John12')
INSERT [dbo].[UserQuiz] ([UserQuizID], [QuizID], [DateTimeComplete], [Score], [Username]) VALUES (2, 1, CAST(0x0000A07900000000 AS DateTime), 50, N'Tim12')
INSERT [dbo].[UserQuiz] ([UserQuizID], [QuizID], [DateTimeComplete], [Score], [Username]) VALUES (3, 1, CAST(0x0000A07B00000000 AS DateTime), 100, N'Rony14')
INSERT [dbo].[UserQuiz] ([UserQuizID], [QuizID], [DateTimeComplete], [Score], [Username]) VALUES (4, 1, CAST(0x0000A07900000000 AS DateTime), 0, N'Tim15')
INSERT [dbo].[UserQuiz] ([UserQuizID], [QuizID], [DateTimeComplete], [Score], [Username]) VALUES (5, 1, CAST(0x0000A07900000000 AS DateTime), 100, N'Tid52')
SET IDENTITY_INSERT [dbo].[UserQuiz] OFF
/****** Object: ForeignKey [FK_Employee_Divisions] Script Date: 08/03/2012 19:36:09 ******/
ALTER TABLE [dbo].[Employee] WITH CHECK ADD CONSTRAINT [FK_Employee_Divisions] FOREIGN KEY([DivisionCode])
REFERENCES [dbo].[Divisions] ([SapCode])
GO
ALTER TABLE [dbo].[Employee] CHECK CONSTRAINT [FK_Employee_Divisions]
GO
/****** Object: ForeignKey [FK_UserQuiz_Employee] Script Date: 08/03/2012 19:36:09 ******/
ALTER TABLE [dbo].[UserQuiz] WITH CHECK ADD CONSTRAINT [FK_UserQuiz_Employee] FOREIGN KEY([Username])
REFERENCES [dbo].[Employee] ([Usename])
GO
ALTER TABLE [dbo].[UserQuiz] CHECK CONSTRAINT [FK_UserQuiz_Employee]
GO
/****** Object: ForeignKey [FK_UserQuiz_Quiz] Script Date: 08/03/2012 19:36:09 ******/
ALTER TABLE [dbo].[UserQuiz] WITH CHECK ADD CONSTRAINT [FK_UserQuiz_Quiz] FOREIGN KEY([QuizID])
REFERENCES [dbo].[Quiz] ([QuizID])
GO
ALTER TABLE [dbo].[UserQuiz] CHECK CONSTRAINT [FK_UserQuiz_Quiz]
GO
And here's the query:
SELECT COUNT(DISTINCT dbo.UserQuiz.Username) AS [Total Number of Participants], dbo.Divisions.DivisionShortcut, dbo.Quiz.Title
FROM dbo.employee INNER JOIN
dbo.UserQuiz ON dbo.employee.Username = dbo.UserQuiz.Username INNER JOIN
dbo.Quiz ON dbo.UserQuiz.QuizID = dbo.Quiz.QuizID INNER JOIN
dbo.Divisions ON dbo.employee.DivisionCode = dbo.Divisions.SapCode
WHERE (dbo.Quiz.IsSent = 1)
GROUP BY dbo.Divisions.DivisionShortcut, dbo.Quiz.Title, dbo.UserQuiz.QuizID
ORDER BY dbo.UserQuiz.QuizID DESC
What should I do to improve it and get what I need?