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SQL VISUAL QUICKSTART GUIDE- P3

SQL VISUAL QUICKSTART GUIDE- P3:SQL (pronounced es-kyoo-el) is the standard programming language for creating, updating, and retrieving information that is stored in databases. With SQL, you can turn your ordinary questions (“Where do our customers live?”) into statements that your database system can understand (SELECT DISTINCT city, state FROM customers;) | Introduction What You ll Need What You ll Need To replicate this book s examples on your own computer you ll need A text editor The sample database A database management system A text editor. Typing short or ad-hoc interactive SQL statements at a prompt is convenient but you ll want to store nontrivial SQL programs in text files. A text editor is a program that you use to open create and edit text files which contain only printable letters numbers and symbols no fonts formatting invisible codes colors graphics or any of the clutter usually associated with a word processor. Every operating system includes a free text editor. Windows has Notepad Unix has vi and emacs and Mac OS X has TextEdit for example. By convention SQL files have the filename extension .sql but you can use .txt or any extension if you prefer. Tips Windows users might want to forgo Notepad for a better alternative such as TextPad 30 U.S. www.textpad.com EditPlus 30 U.S. www.editplus.com or Vim free www.vim.org . You can type SQL programs in a word processor such as Microsoft Word and save them as text-only files but that practice causes maintenance problems and professionals consider it to be bad form . The sample database. Most examples in this book use the same database described in The Sample Database in Chapter 2. To build the sample database follow the instructions in Creating the Sample Database in Chapter 2. If you re working with a production-server DBMS you might need permission from your database administrator to run SQL programs that create and update data and database objects. A database management system. How do you get SQL You don t you get a DBMS that understands SQL and feed it an SQL program. The DBMS runs your program and displays the results as described in the next chapter. xx 1 DBMS Specifics You need a database management system to run SQL programs. You can have your own private copy of a DBMS running on your desktop local computer or you can use a shared DBMS over a network.