Based on the fact that we are developing a demo blog system and mainly focusing our interests upon how to make use of the ASP.NET AJAX server-side techniques, I choose to use the simplest two-tier architecture to build the sample rather than fall back on the three-tier or even the newest ASP.NET MVC ones (all of which are recommended architectures in practical case).

As is well known, in the two-tier architecture you can directly access the backend database in each page of the presentation tier without implementing the individual database interface. Advantages and disadvantages are apparent: the developing and debugging processes are greatly simplified while the maintenance will become fussy and even more difficult.

At any rate, let us examine the two-tier architecture applied to this mini blog system, as is depicted in Figure 3.

Figure 3: The two-tier architecture utilized in this mini blog system

Apparently, in the two-tier module we are able to directly manipulate the backend system via .aspx web pages (the presentation tier). In detail, through the web pages, we can directly achieve all the operations such as adding, modifying, or deleting the data persisted in the SQL Server database.

System Functionality Modules

The sample website, named AajxMiniBlog in this article, provides different functionalities according to the corresponding role of the users. On the whole, there are two kinds of roles in this system: the administrator (and, for simplicity, the blog host) and the common user (any common surfers). The former owns the right of category management, blog management, comments management, and hyperlinks management while the common users are assigned the rights to browse blogs and related comments, leave a word, as well as make comments on their interested blogs.

As of now, you can clearly understand that the whole system is easily divided into two parts from the view point of the user roles, as in illustrated in Figure 4 and Figure 5.

Figure 4: The blog administrator modules

Figure 5: The common users related modules

With the general architecture and modules in mind, let us roll up our sleeves to start to work.  But first of all, let us dissect at the database design and its related tables together with the relationships between them one by one.