beginning t-sql 2012 2nd edition

Shaw Kellenberger Shelve in Databases / MS SQL Server User level: Beginning www.apress.com SOURCE CODE ONLINE RELATED BOOKS FOR PROFESSIONALS BY PROFESSIONALS ® Beginning T-SQL 2012 Beginning T-SQL 2012 starts you on the path to mastering T-SQL. It shows you how to implement best practices for writing T-SQL, avoid common errors, and write scalable code for good performance. Beginning T-SQL 2012 begins with an introduction to databases and normalization as well as SQL Server Management Studio. The authors then teach you one feature or concept of T-SQL at a time, with each new skill building on the ones you previously learned. The book contains many simple examples to illustrate the techniques covered and get you quickly using them. With Beginning T-SQL 2012, you’ll learn how to: • Write accurate queries that are scalable and perform well • Combine set-based and procedural processing, obtaining the best from both worlds • Embed business logic in your database through stored procedures and functions • Simplify your work with new and advanced features, such as common table expressions and virtual tables • Enhance performance by knowing when to apply features such table value parameters and when not to With an emphasis on best practices and sound coding techniques, Beginning T-SQL 2012 gives you hands-on knowledge of this important language. It teaches you how to write code that will help you to achieve the best-performing applications possible. SECOND EDITION www.it-ebooks.info For your convenience Apress has placed some of the front matter material after the index. Please use the Bookmarks and Contents at a Glance links to access them. www.it-ebooks.info iv Contents at a Glance  Foreword xvi  About the Authors xviii  About the Technical Reviewer xix  Acknowledgments xx  Introduction xxi  Chapter 1: Getting Started 1  Chapter 2: Writing Simple SELECT Queries 35  Chapter 3: Using Functions and Expressions 79  Chapter 4: Querying Multiple Tables 131  Chapter 5: Grouping and Summarizing Data 169  Chapter 6: Manipulating Data 203  Chapter 7: Understanding T-SQL Programming Logic 241  Chapter 8: Working with XML 285  Chapter 9: Moving Logic to the Database 311  Chapter 10: Working with Data Types 367  Chapter 11: Writing Advanced Queries 391  Chapter 12: Where to Go Next? 419  Index 423 www.it-ebooks.info xxi Introduction I never thought I’d be writing a technical book. I have a MA in English Literature so I always pictured myself sitting in an oak paneled room surrounded by books and attentive students listening to me pontificating on the latest criticism of 19 th Century novels. It didn’t take me long to realize though that path wasn’t for me and I really wasn’t cut out for a life in academia. But now I was an ex-English major working in a book store, starting a family and with little career prospects. Working in a bookstore did offer some advantages. One advantage was the easy access to technical books. I had endless access to books just like the one you are reading now. I thought to myself, why not read these books, learn from them, and try working in IT? I didn’t see a need to go back to school in order to learn IT. I had the books, I had the computer at home to work on, and I had the goal of acquiring an IT certification. I eventually passed the certification exam and soon after that I got my first break into IT working for a small consulting company. So, why does any of this matter? The point is that many, if not most, of the people working in IT today didn’t plan to be in IT. They come from a diverse background. The one thing that binds them together is their desire to learn and study to become experts in their field. They all started down the path by reading books just like the one you are holding. They made a decision to start an IT career. This is an important book because it’s the beginning. The book is the stepping stone to becoming a professional. Although it isn’t the great American novel I had hoped to someday write, it was still a pleasure and honor to have been asked by Kathi and Apress to revise it because, unlike a novel, this book has practical, real world applications. I also take pride in the fact I have given back a little for the benefits similar books have given me in the past. Enjoy the book and never stop learning. -Scott Shaw www.it-ebooks.info C H A P T E R 1 1 Getting Started If you are reading this book, you probably know about T-SQL. T-SQL, also known as Transact-SQL, is Microsoft’s implementation of the Structured Query Language (SQL) for SQL Server. T-SQL is the language that is most often used to extract or modify data stored in a SQL Server database, regardless of which application or tool you use. SQL Server 2012 T-SQL is based on standards created by the American National Standards Institute (ANSI), but Microsoft has added several functionality enhancements. You will find that T-SQL is a very versatile and powerful programming language. T-SQL consists of Data Definition Language (DDL) and Data Manipulation Language (DML) statements. This book focuses primarily on the DML statements, which you will use to retrieve and manipulate data. The book also covers DDL statements, which you will use to create and manage objects. You will learn about table creation, for example, in Chapter 9. In this chapter, you will learn how to install a free edition of SQL Server and get it ready for running the example code and performing the exercises in the rest of the book. This chapter also gives you a quick tour of SQL Server Management Studio (SSMS) and introduces a few concepts to help you become a proficient T-SQL programmer. Installing SQL Server Express Edition Microsoft makes SQL Server 2012 available in six different editions, including two that can be installed on a desktop computer or laptop. If you don’t have access to SQL Server, you can download and install the SQL Server Express edition from Microsoft’s web site at www.microsoft.com/express/sql/download/default.aspx. To fully take advantage of all the concepts covered in this book, download SQL Server 2012 Express with Tools. You may notice a new LocalDB option for SQL Server Express; LocalDB is an extremely lightweight version of SQL Server that doesn’t include any configuration options or tools. Since you will need the tools for this book you don’t want to download the LocalDB version. Be sure to choose either the 64-bit or 32-bit download according to the operating system that you are running. The Express edition will run on the following operating systems available at the time of this writing: Windows Server 2008 SP2, Windows Server 2008 R2 SP1, Windows 7 SP1, Windows Vista SP2. Note that SQL Server 2012 is not compatible with Windows XP.  Note SP is shorthand for Service Pack, so SP2 refers to Service Pack 2. A service pack is an update to the operating system or to other software that fixes bugs and security issues. www.it-ebooks.info CHAPTER 1  GETTING STARTED 2 Here are the steps to follow to install SQL Server Express: 1. Once you have downloaded the SQL Server 2012 Express edition installation file from Microsoft’s site, double-click the file to extract and start up the SQL Server Installation Center. Figure 1-1 shows the Planning pane of the SQL Server Installation Center once the extraction has completed. You may need to click on Planning in the left-hand side to see these options. Figure 1-1. SQL Server Installation Center’s Planning pane 2. To make sure that your system meets all the requirements to install SQL Server Express, click the System Configuration Checker link, which opens the Setup Support Rules screen (see Figure 1-2). Click “Show details” or “View detailed report” to see more information. Click OK to dismiss the screen when you are done. www.it-ebooks.info CHAPTER 1  GETTING STARTED 3 Figure 1-2. The Setup Support Rules details page 3. If your system doesn’t meet the requirements, click the Hardware and Software Requirements link on the Planning pane of the SQL Server Installation Center, which will take you to a web page on Microsoft’s site. Be sure to scroll down the web page to find the information for the Express edition. The hardware requirements are not difficult to meet with today’s PCs. 4. Once you are certain that your computer meets all the requirements, switch to the Installation pane, shown in Figure 1-3, and click “New SQL Server stand- alone installation or add features to an existing installation.” The Setup Support Rules screen you saw in step 2 will display again, but the behavior will be different this time. Click OK to dismiss the Setup Support Rules screen, and an installation wizard will begin. www.it-ebooks.info CHAPTER 1  GETTING STARTED 4 Figure 1-3. The Installation pane 5. You may or may not see a Setup Support Files screen at this point. If you do see it, click Install. 6. Select Express from the drop-down and click Next on the Product Key screen when installing SQL Server Express edition. No need to have a key since this is a free edition! Accept the license terms and click Next. 7. Some more checking of your system will take place. You may get a warning about your firewall (Figure 1-4), especially if you are installing on a workstation. The warning will say to open ports required for other systems to access your SQL Server. You can ignore that warning unless you do really want to open up your system. Click Next to continue. www.it-ebooks.info CHAPTER 1  GETTING STARTED 5 Figure 1-4. More system checks 8. If you have a previously installed instance of SQL Server on your computer, the installation will prompt you to either update an existing instance or install a new instance on the Installation Type screen. Select to install a new instance and click Next. If you don’t have a previous install, select the option “SQL Server Feature Installation” and click Next. 9. On the Feature Selection screen (Figure 1-5), make sure that “Database Engine Services,” “Full-Text and Semantic Extractions for Search,” and “Management Tools – Basic” are selected before clicking Next. If a previous SQL Server 2012 R2 installation is in place, the Management Tools check box might be grayed out since you need to install it only once per computer. www.it-ebooks.info CHAPTER 1  GETTING STARTED 6 Figure 1-5. The Feature Selection screen 10. Figure 1-6 shows the Instance Configuration screen, and it is very important. Here you can choose to install a default instance or a named instance. If you have any SQL Server instances already installed, possibly an earlier version such as 2008 R2, they will show up in the list on this screen. Each instance must have a unique name, so you must avoid using any existing instance names. See the sidebar “Named Instances” for more information about naming SQL Server instances. The Express edition installation installs the named instance MSSQLSERVER by default. Use the name MSSQLSERVER if you can; otherwise, type in a unique name. Figure 1-6 shows the instance configuration screen. Click Next. www.it-ebooks.info [...]... There is even a version that can be installed on smart phones (Compact edition) Search for the article “Features Supported by the Editions of SQL Server 20012” in SQL Server Books Online for more information about the editions and features of each Table 1-1 gives an overview of the editions available Table 1-1 SQL Server 2012 Editions Edition Usage Expense Compact Occasionally connected systems including... learn more by reading Beginning Relational Data Modeling, Second Edition, by Sharon Allen and Evan Terry (Apress, 2005) 23 www.it-ebooks.info CHAPTER 1  GETTING STARTED Editions Microsoft makes SQL Server available in many editions, including a free edition called Express that can be distributed with applications or used to learn about SQL Server and several expensive, full-featured editions (Standard,... 1-1 You will need to change the path to match the location where you downloaded the AdventureWorks2012 data file Figure 1-13 shows how your screen should look Listing 1-1 Script to Create the AdventureWorks2012 Database CREATE DATABASE AdventureWorks2012 ON (FILENAME = ':\\AdventureWorks2012_Data.mdf') FOR ATTACH_REBUILD_LOG ; Figure 1-13 The sample database install You should now have... window you will type and run queries as you learn about T-SQL The following steps will guide you through writing your first query in the Query Editor 1 Make sure your SQL Server instance is selected in the Object Explorer, and click New Query, which is located right above the Object Explorer, to open the Query Editor window 2 Select the AdventureWorks2012 database from the drop-down list on the left if... site You will learn how to write T-SQL from reading this book, but I recommend that you check Books Online frequently to learn even more! Using SQL Server Management Studio Now that you have SQL Server, SQL Server Books Online, and the sample database installed, it’s time to get acquainted with SQL Server Management Studio (SSMS) SSMS is the tool that ships with most editions of SQL Server, and you... Express with Tools as outlined earlier, you should be able to find SSMS by selecting Start  All Programs  Microsoft SQL Server 2012  SQL Server Management Studio SSMS is your window into SQL Server You can manage your database, create scripts, and—most importantly—execute T-SQL code and see the results Launching SQL Server Management Studio Launch SSMS by selecting Start  All Programs  Microsoft... application To do that, you will most likely use a programming language such as Visual Basic NET or C# Calls to SQL Server via T-SQL can be made within your application code or through a middle tier such as a web service Regardless of your application architecture, at some point you’ll use T-SQL SQL Server does have a very nice reporting tool called Reporting Services that is part of the business intelligence... Management Studio if it is not already running, and connect to the SQL Server instance you installed in the “Installing SQL Server Express Edition section Expand the Databases folder to see the databases installed on the SQL Server You should be able to see the AdventureWorks2012 database, as in Figure 1-28 25 www.it-ebooks.info CHAPTER 1  GETTING STARTED Figure 1-28 The databases Within a database, you... and temporal data Start SQL Server Management Studio if it is not running already, and connect to the SQL Server you installed in the “Installing SQL Server Express Edition section Expand the Databases section Expand the AdventureWorks2012 database and the Tables section Locate the HumanResources.Employee table, and right-click it Select the Design option to view the properties (see Figure 1-29) 27... normalization is beyond the scope of this book, but it is helpful to understand why databases are normalized To learn more about normalization, see Pro SQL Server 2012 Relational Database Design and Implementation by Louis Davidson and Jessica Moss (Apress, 2012) Figure 1-31 shows how a database design might look before it is normalized The example is of an order-entry database There is one table, and that table . Server User level: Beginning www.apress.com SOURCE CODE ONLINE RELATED BOOKS FOR PROFESSIONALS BY PROFESSIONALS ® Beginning T-SQL 2012 Beginning T-SQL 2012 starts you on the path to mastering T-SQL. It. you how to implement best practices for writing T-SQL, avoid common errors, and write scalable code for good performance. Beginning T-SQL 2012 begins with an introduction to databases and. this book, you probably know about T-SQL. T-SQL, also known as Transact-SQL, is Microsoft’s implementation of the Structured Query Language (SQL) for SQL Server. T-SQL is the language that is most