Jsp, Tomcat, J2Ee, Linux Web Hosting, Hibernate Programming Blog

However, if you were to try this technique right now using only what s covered in the book up to this point there s a good chance yours wouldn t work. That s because there are rules to follow to get this sort of thing to work two in particular: Every table on the one side of a one-to-many relation must have a primary key, a field that uniquely identifies each record in that table. In this example, both the users and items tables must have a primary key. The transaction table must contain at least two fields whose names and data types match the names and data types of the two tables on the one side of the relationships. To understand and apply those rules, the first order of business is to understand data types and primary keys. Let s start with data types. SQL Server Tables Every column in every table has a data type that defines the type of data stored in the column. To view each column s data type, open the table definition, rather than the table data. When you open a table definition, you don t see any of the actual data that s stored in the table. Instead, you see the structure of the table. The table s structure shows the name, data type, and whether the field allows nulls. To see an existing table s structure, right-click the table s name in Database Explorer and choose Open Table Definition, as shown in Figure 11-9. For example, if you right-click the aspnet_Users table in Database Explorer and choose Open Table Definition, you see field names listed down the left side of the grid that opens. Each of those names represents a column that appears at the top of the aspnet_Users table when you re viewing the table s data. To the right of each field name is the Data Type of that field, as shown in Figure 11-10. Figure 11-9: How to view a table s structure (definition). Chapter 11: SQL Server Crash Course 227
We recommend high quality webhost to host and run your jsp application: christian web host services.

There s also a one-to-many relationship between items and users. The Transactions table, once again, provides the map describing which users purchased an item. Pick any one item, say 10003, from the Items table. Find records in the Transactions table that have 10003 in their ItemId field, and you have a link back to each user that purchased that product, as shown in Figure 11-7. In real life, of course, you don t draw lines between records in tables to get information. In fact, you don t look at the tables at all instead, you create queries to get information. However, while I m on the subject of lines that connect things between tables, any time you extract data from all three of the tables (users, transactions, and items), your query must contain fields of all three tables. And the primary and foreign keys that link the tables must be connected by join lines in that query, as shown in Figure 11-8. We ll discuss the roles of the primary and foreign keys in detail as we progress through the chapter. So that s how database design works, in a conceptual sense. When there is a natural many-to-many relationship between items in two separate tables, you need a third table that contains records stating who purchased what. That third table provides the many-to-many link needed to extract meaningful data from the tables. Figure 11-8: A query s view of connecting lines between tables. Users Transactions Items Figure 11-7: Trace any one ItemId back to users who bought that item. 226 Part III: Personalization and Databases
We highly recommend you visit web and email hosting services if you need stable and cheap web hosting platform for your web applications.

Now, imagine that user Carol (UserId 66cd…) purchases item 10003. The Transactions would need a new record with 66cd in its UserId field and the 10003 in its ItemId field. If you then trace an imaginary line from the user to the transaction to the item, you ll see how the record in the Transactions table provides the link from a specific user to a specific item purchased, as in Figure 11-5. Every time a user purchases something, the Transactions table grows by one record. As time goes by, the Transactions table continues to grow, perhaps to thousands of records. Each record represents a single transaction where a specific user purchased a specific product. Recall that the natural many-to-many relationship between users and items is actually two one-to-many relationships. Any one user might purchase many items, and any one item might be purchased by many users. The Transactions table provides the map that allows code to find all transactions by any one user. No matter how many records are in the Transactions table, that table still provides the one-to-many link from users to items. To illustrate, pick one user, such as Carol (UserId 66cd…). Each record in the Transactions table that has 66cd… is a transaction made by that user. The ItemId field in Transactions identifies exactly which item the user purchased, as shown in Figure 11-6. Users Transactions Items Figure 11-6: One-tomany link from a user to many products purchased. Users Transactions Items Figure 11-5: Third Transactions table links user to item purchased. Chapter 11: SQL Server Crash Course 225
You need excellent and relaible webhost company to host your web applications? Then pay a visit to Inexpensive Web Hosting services.

of data. It, and other products like it, exist mainly because in the real world, there are natural one-to-many relationships among different types of data. For example, suppose your site offers some kind of items to users. The items might be products you sell, courses you offer, Web seminars that people sign up for, or something like that. In cases such as these there are two natural one-to-many relationships between users and the items being offered: Any one user might purchase many items. Any one item might be purchased by many users. Any time you have two one-to-many relationships like that, you have what s called a many-to-many relationship. You have many users purchasing (or enrolling in, or attending) many items. To illustrate, let s look at simplified versions of the aspnet_Users table and a table of items that the site offers to users. At the left side of Figure 11-4 is a table showing a couple of columns and some rows from a table of users. Each record in that table represents a single user account. On the right side is a simple Items table. Each record in that table represents a single item offered to users. In between the two tables is the burning question How do I connect these? The answer is pretty straightforward: By creating a third table that keeps track of who purchased what. It might help to think of it this way. Each time a user purchases a product, that s a transaction. You need to keep track of these transactions specifically, who purchased what and that requires two pieces of information per transaction: who (a UserId), and what (an ItemId). So, at the very least, this third table (which I ll name Transactions) must contain two fields: One field to record the user s identification (UserId), and the other to record the item purchased (ItemId). You can imagine this as a table with two fields named UserId and ItemId between the aspnet_Users table and the Items table. Users Items How do I connect these? Figure 11-4: Sample aspnet_ Users and Items tables. 224 Part III: Personalization and Databases
If you are in need for chaep and reliable webhost to host your website, our recommendation is http web server services.

For example, by the time I got to this part of the book, I had created seven user accounts through the Web Site Administration Tool. Every account you create becomes a record in aspnet_Users. So opening my aspnet_Users table shows that it contains seven records, as shown in Figure 11-3. Don t add, change, or delete data in any of the aspnet_ tables manually through Database Explorer. Always use the Web Site Administration Tool to manage membership data. To close an open table, just click the Close (X) button in the upper-right corner, just as you d close anything else that s open in the Design surface. One-to-many, many-to-many SQL Server 2005 is a relational database-management system (RDBMS) that not only stores data, but can also define multiple relationships among items Figure 11-3: The aspnet_ Users table data. Figure 11-2: Automatically created tables in a Membership site. Chapter 11: SQL Server Crash Course 223
In case you need quality webspace to host and run your web applications, try our personal web hosting services.

Crash Course in Database Design Database design is an enormous topic that could easily fill several books the size of this one and has so I can t get into all the details here. But I can get you in the ballpark and clear up some of the important buzzwords that apply to all relational databases. Tables, rows, and columns The data (information) in a SQL Server database is organized into tables. Each table consists of rows (also called records) and columns (also called fields). Figure 11-1 illustrates the terms, using a sample table named Items. The field names (that is, the column names) are ItemId, OurItemId, ItemName, and ItemPrice. The table contains five rows (records), which happen to be numbered 10001, 10002, 10003, and so forth. When you set up your site for Membership, VWD automatically creates several tables for you. To see those tables, first make sure your Web site is open in Visual Web Developer, then click the Database Explorer tab or choose View. Database Explorer from the menu bar. To see the tables that are already in your database, expand the Data Connections, ASPNET.MDF, and Tables categories (if they re showing a + sign). Each item under the Tables heading represents a single table of data. The names of tables that VWD automatically creates all start with aspnet_ as shown in Figure 11-2. Each one of those tables contains rows and columns. To see the actual data that s stored in a table, right-click the table name and choose Show Table Data. For example, if you right-click aspnet_Users and choose Show Table Data, the aspnet_Users table opens. The table will contain one record for each user account you ve created. Rows (records) Columns (fields) Figure 11-1: A sample database table. 222 Part III: Personalization and Databases
We highly recommend you visit web and email hosting services if you need stable and cheap web hosting platform for your web applications.

Chapter 11 SQL Server Crash Course In This Chapter Exploring database design Designing a database with tables and primary keys Creating your own SQL Server tables Linking tables Abig part of any dynamic data-driven Web site is the database that contains data for the site. Visual Web Developer allows you to use either Microsoft Access (.mdb files) or SQL Server 2005 (.mdf files) for storing data. Of the two, a SQL Server database provides better scalability and supports a greater number of simultaneous users. That s why it s the database most people will likely want to use (or would, if they knew what we know), so that s the one that gets the focus in this book. As its title suggests, this chapter is a quick crash course in using SQL Server as the database for your Web site. You ll discover what SQL Server is, and how to create tables to store the data your Web site needs. You ll also get the lowdown on SQL, Structured Query Language, the tool you use to extract specific data from the database to display on Web pages. If you re already familiar with a database program like Microsoft Access, the most noticeable feature of SQL Server is that it has no user interface no program window you can open from the Start menu. There s no table designer, no forms designer, nothing. The reason for that is simple: Microsoft Access is an application program that has to perform multiple tasks for a wide range of users but SQL Server is a lot more specialized; it s just a server. As a server, SQL Server 2005 is designed to provide data storage and Access to some other program rather than to a human who is sitting at the mouse and keyboard. The working interface for SQL Server isn t in its own separate program window. It s right in Visual Web Developer.
From our experience, we can recommend PHP Web Hosting services, if you need affordable webhost to host and run your web application.

The beauty of this approach is that every page opens with the default theme applied, instead of with no theme applied. As you create and review your pages, you know exactly where each item s style is coming from. The default theme is only the default, in the sense that it s applied only when something else doesn t override it. Any theme that s applied programmatically will override the default theme. Figure 10-18: Setting a default theme in Web. config. 220 Part III: Personalization and Databases
If you are in need for chaep and reliable webhost to host your website, our recommendation is http web server services.

Page.Theme: The theme s style settings override any local style settings. Page.StyleSheetTheme: Behaves more like a Cascading Style Sheet local style settings still take precedence over styles defined in themes. Choosing one option or the other is largely a matter of personal taste. The advantage of using Page.Theme is that you know that whatever is defined in the theme rules. You won t get any unpleasant surprises when a control or a chunk of text ignores the theme because you previously set some style that s now overriding your theme. The disadvantage to using Page.Theme is that if ever there was a need to override a theme-defined style for a particular control, there wouldn t be any way to do it, other than to create a special style rule for that one control. In the long run, you re probably better off sticking to the Page.Theme approach and allowing themes to take precedence. You don t want to end up with hundreds of controls on hundreds of pages, all doing their own things and ignoring your themes. That can just make using (not to mention maintaining) the site all the more confusing and more laborious. Defining a Site-Wide Default Theme In the code samples above, themes are applied to pages programmatically in the sense that code defines which theme is used for any given page based on the user s PreferredTheme property. At a higher level, you can define a default theme to be used by all the pages in your site. You do so in the Web.config file for your site using either of the following syntaxes:
where ThemeName is the name of a theme folder. For example, if you create a theme folder named DefaultTheme, and want to apply that theme to all pages in the site, you add the following line to your Web.config file:
Be sure to put the tag between the and tags in Web.config (as in Figure 10-18). Chapter 10: Using Themes 219
Looking for affordable and reliable webhost to host and run your business application? Then look no more and go to servlet web hosting services.

You ll need the similar style rules in each theme folder s StyleSheet.css page, though the colors and other stylistic options you choose would vary from one theme folder to the next. In the code-behind file for the Master Page (MasterPage.master.cs in my example), add Page_PreInit code to apply the user s preferred theme. The code is no different from the code you d use in an .aspx page. So, in my example, it would look like this: public partial class MasterPage : System.Web.UI.MasterPage { // On pre-initialization apply user s preferred theme. protected void Page_PreInit(object sender, EventArgs e) { if (Profile.PreferredTheme == null) { Page.Theme = DefaultTheme ; } else { Page.Theme = Profile.PreferredTheme; } } } Whether to allow users to customize Master Pages is really something you have to decide for yourself. There s no rule that says a site can only have one Master Page. The fact is, a site can have as many Master Pages as you like. As an alternative to allowing users to customize the Master Page for your site, you could have two Master pages. Use one fixed-and-unchanging Master Page for general pages. Then create a second Master Page for privileged content only, and allow users to set styles within that Master Page only. Other Ways to Apply Themes In all of the above examples of applying themes, you used the syntax Page.theme=Profile.PreferredTheme to apply the user s preferred theme to a page. Here s another syntax you can use as an alternative: Page.StyleSheetTheme = Profile.PreferredTheme; The difference between using Page.Theme and using Page.StyleSheetTheme is as follows: 218 Part III: Personalization and Databases
Please visit Domain Name Hosting services for high quality webhost to host and run your jsp applications.