Introduction

In this series of articles, we'll try to build a popular YouTube-like video playing website using ASP.NET related techniques. After you read this series, you may draw such a conclusion: so simple to construct my own video playing website! But wait a moment: you should have to grasp the necessary ASP.NET fundamentals. In another word, this series will involve quite a few ASP.NET techniques, such as C# programming tips, Microsoft SQL Server 2008, ASP.NET AJAX server-side modules, browser-side Flash player, Internet Information Server, and so forth.

Development Background

With the rapid development of Internet, showing self-expression by text is no longer a mainstream. Podcasting sites, e.g. the famous youtube.com, are welcomed by the majority of users who try to show themselves through video displays. Facts speak louder than eloquence. Millions of videos are uploaded to the podcast sites and the online video watching or clicking times can exceed a million times. Some people can submit their videos to the podcast sites, while others can watch these videos and make comments upon them, which in a great degree helps to enhance communication between users. And on the other hand, a successful video site will bring huge business profits to site owners.

Requirement Analysis

For a long time, people's video made by themselves can only be stored in their computers. If they want to share these wonderful homemade videos with friends and family, they have to resort to some traditional methods (such as burning CDs, etc.) and mail it to them, consuming time and laborious. If we can develop some video site, you can upload and share video to a friend, it would be a pleasure for everyone to share the process.

Due to the above demand, the more welcomed podcast websites appear. Podcasting network is a platform which can assist users to show themselves through their published various forms of videos. In a podcast network, users can be registered as a member of the site, and then they can publish their own videos to the site. Other users can enjoy these videos released by the site members; and also, they can even express their views or opinions towards the products.

In addition, podcast sites can also provide point ranking functionalities. For example, the more a member posts videos, the higher points he can obtain. The site's backend administration module can manage the videos via various kinds of policies. Members' released videos must be reviewed by an administrator before they can be displayed in the front page. If a member has posted the offending video, the administrator has the right to freeze the account.

System Design

Now, let's start from the system design phase. First, look at the system target.

System target

An ideal video site should at least achieve the following objectives:

• User-friendly and beautiful interface, safe and reliable data storage.
• Ordinary users can watch the videos by category, such as jokes, sports, and so on.
• Powerful video search capabilities, to ensure the flexibility of video queries.
• Ordinary users and members can both make comments on the videos.
• Member points management. The more products a member of the video site uploads, the higher the points he can receive.
• Video legality audit support. If a member is found to publish illegal videos, the administrator can use this function to freeze his account.
• Video ranking support mainly based on video hit rates.
• Personal management center. Users can manage their own uploaded videos.
• The system administrator can control the video ranking, the site's dynamical advertisements, as well as recycling playing arrangement.
• Maximize the maintenance and operability.

Business flow chart

To give a more intuitive understanding with the video playing website, let's first depict the business flow chart of the system using graphics.

Figure 1: Business flow chart of the system

Backend system functionalities structure

According to the audit characteristics of a podcasting site, we can design the basic backend administrator audit functionalities structure, as shown in Figure 2.

Figure 2: Backend system administrator audit functionalities architecture

Database Design

In this system, the database is named playVideo designed using SQL Server 2008. There are eight tables contained in the database playVideo. For the readers to gain a clearer idea of the database design, we'll give to you both the graphical E-R representation and the table structure details.

Database conceptual design

According to the preceding requirement analysis, system flow chart introduction, and system functionality structure, we can easily design the main database entity objects used by the system.

As explained above, after the registered members publish their videos, the administrator needs to audit the video contents and all related info in the backend management. If illegal, then these videos will be refused. The video detailed info related E-R diagram is given in Figure 3 below.

Figure 3: Video detailed info related E-R diagram

Obviously, without users' comments even seemingly-wonderful videos will be eclipsed. We can also easily design the video comment info related E-R diagram, as shown in Figure 4.

Figure 4: Video comment info related E-R diagram

After the splendid videos get recommended by surfers, the degree of concern will be greatly enhanced. The video ranking info related E-R diagram is given in Figure 5.

Figure 5: Video ranking info related E-R diagram

If good videos can be found and recommended by users, we can exhibit the related info by setting up some video voting module. The video poll info related E-R diagram is shown in Figure 6.

Figure 6: Video poll info related E-R diagram

Database Logical structure design

Now that the database E-R diagrams has been introduced, the next task should be designing the related tables according to the existing E-R info.

Now, let's look at the detailed table structure definitions. The first one is table userRegister.

Table 1: Structure for table ‘userRegister’

Table VideoInfo contains all the video info that users upload. Below is the structure for table VideoInfo.

Table 2: Structure for table ‘VideoInfo’

Table VideoIdea is used to hold all video related comment info of customers. Below gives the structure for this table.

Table 3: Structure for table ‘VideoIdea’

Table VideoTaxis contains all ranking info of videos per month. Below indicates the structure for this table.

Table 4: Structure for table ‘VideoTaxis’

Table VideoPoll is used to hold all polled user IP and video Id. Below indicates the structure for this table.

Table 5: Structure for table ‘VideoPoll’

Table bulletin contains the bulletin related info. Below indicates the structure for this table.

Table 6: Structure for table ‘bulletin’

There are still two tables left, manageUser and userInfo. Since they are commonly-seen user info management related ones; we'll no more list them.

Design Common Classes

To improve development efficiency and facilitate future maintenance, some common helper classes are necessary to a good-shaped application. In our case, we've written two helper classes located under the folder App_Code. The first helper class is named operateData, which aims to ease ordinary database operations. The second helper class is operateMethod, inside which there are hidden several methods commonly-used somewhere in the application.

The Helper Class operateData

The first important method defined in the class operateData is execSql. This method is used to execute record add, insert, and update operations with the tables. It returns a bool type to indicate whether the current operation is successful or not. The only argument passed into the method is a typical SQL string which specifies the target table operation.

Another method worth noticing is getTier, which is used to return specified column related value. The only argument passed into the method is also a SQL string to decide the corresponding operation. It returns a string type to indicate the returned value.

The third method defined in the helper class operateData is getRows. As the name implies, this method will return all the data in the target table. But note that this method returns a DataTable object, with only an argument passed in to give the required SQL operation.

Another method to take notice of is login. This method is used to check whether the current user has successfully logged in or not. The returned value True indicates login success, while False shows failure.

Above we've used SqlCommand.Parameters to filter out the illegal characters to prevent from the notorious SQL injection attack.

Now, let's research into another helper class operateMethod.

The Helper Class operateMethod

There are some important methods which deserves your attention. The first one is called changeVideoType, which is responsible to transform the users' uploaded videos into the .flv format and then store them under corresponding folders. There are three arguments: the first one specifies the file to transform, the second corresponds to the transformed file, and the third is used to store the video capturing file.

As mention in the above method, our system provides the function of video capturing. This is achieved through the method catchImg. There are two arguments passed into this method: the first specifies the file whose video will be captured, the second corresponds to the file to hold the captured image.

Another method commonly used in web site programming is named filtrateHtml, which is used to transform some invalid characters into valid ones that can be identified by the backend system.

The corresponding method whose function is opposite to the above method is named resumeHtml, as follows.

Summary

In this first part of the series, you've learned the background to build a video site. Then we made simple requirement analysis and made clear the design target. And next, you got familiar with the business flow chart of our sample system, as well as the system functionality architecture. Then, we introduced the sample database named playVideo, which contains eight tables. And finally, we introduced two fundamental coding helper classes, operateData and operateMethod, which will help to greatly simplify the development and later maintenance of the system. Starting from the next part, we'll dive into the concrete web page design.

About Xianzhong Zhu

I'm a college teacher and also a freelance developer and writer from WeiFang China, with more than fourteen years of experience in design, and development of various kinds of products and applications on Windows platform. My expertise is in Visual C++/Basic/C#, SQL Server 2000/2005/2008, PHP+MyS... This author has published 81 articles on DotNetSlackers. View other articles or the complete profile here.

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Discussion

Subject	Author	Date
great	Mike Garret	11/4/2011 7:53 AM
great article, it's a must read for ASP.NET beginners. i'm looking forward for the next articles Reply | Permanent link
Problem	Shakti Singh	4/4/2012 6:03 AM
hello sir.. it's a very gr8t tutorial you have provided..thanks for it..  but when i tried to use it for learning... in register page it asking for userInfo database which u havn't told us how to built. so please provide me the essential figure of userInfo & usermanage table :) plz sort mine problem sir. Thank you. Reply | Permanent link

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