Excellent companion to the series
Rating:
5 / 5
In this companion to Practical SQL: The Handbook, Practical SQL: The Sequel picks up where the handbook left off and explores tasks related to the daily life of a database. The author takes a hands-on approach to taking basic knowledge of SQL and extending it to solving real world problems. Like most programming languages, SQL is a language that is best learned by doing. Entering queries and seeing what happens will get your further along than textbooks full of relational theory. It's a bit like walking: if you were to think about all the bones in your leg and how they work, you would probably fall down. There are plenty of examples for you to try, which later become prototypes for your own queries.Working on a daily basis with web applications, the Practical SQL Handbook is always within reach and is the reference I turn to whenever I run into a SQL query that tests the limits of my knowledge, despite several years of SQL experience. Writing SQL can often be tricky. Many concepts are difficult to grasp even for the experienced, such as working with aggregates or joins and unions, which often have me returning to the handbook. I expect Practical SQL: The Sequel will become a well-thumbed companion to the handbook. This book covers several important issues often overlooked by general SQL tutorials or theory and not covered at all by vendor manuals. This book is aimed at the person who has learned basic SQL and is moving on to greater things. You will not find basic relational database theory in this companion to Practical SQL: The Handbook, but you will find a balanced guide to learning the practical techniques for solving the SQL puzzles that crop up in the real world outside the classroom. Most working database applications employ SQL that bears little resemblance to the relational concepts and idealized examples found in textbooks or classrooms. Yet at the other extreme, the new SQL user is often frustrated to discover existing references are little more than technical manuals or vendor brochures touting the latest gimmick. This text helps you make the transition from the idealized forms of the classroom to the practical solutions used in everyday database work. It should not be dismissed as a sort of "vocational" text only for those who get their hands dirty. This book offers solid advice for anyone working with relational database systems. A chapter is devoted to recognizing, finding, correcting and removing "dirty data." Such as duplicate information, or nearly duplicate information, such as you are probably familiar with junk mail that comes to your mailbox with several slightly different spellings of your name. In the real world you often inherit data that has been collected without concern for integrity checks. Much of the work a database is expected to do requires searching through data for items matching some condition. This is executed through the WHERE clause, and is the place to start looking for ways you can improve SQL performance merely by paying attention to how you write SQL. In her foray into query tuning, the author explains how to avoid unnecessary table scans provoked by a variety of queries where a subtle difference of usage enables or disables employment of speed enhancing indexes. Or when indexing a column has no practical result. Most database systems provide some method for automatically generating unique numbers as data is inserted. Unfortunately, there is no standard among vendors for how autonumbering is implemented. The author compares examples from the most popular enterprise systems and shows examples of usage. The concept of finding the top-N items in a result set is discussed, which is central to many web applications user interfaces. Useful for navigating the database in "browse n-items" displays, data hiding, "top ten" lists, finding the five best customers, the lowest selling books and etc. A chapter is devoted to translating values, an often overlooked subject. Translation is mapping the arcane codes used to represent values into something readable by human beings. In order to save space and make references clearer to computers, frequently numbers or letter-number codes are used to signify a particular value. Making theses codes readable by people is often a chore, one that requires an inordinate amount of the programmer's attention that might be better spent elsewhere. The text covers various methods of translation, ranging from automatic CASE/DECODE features to doing it yourself using "point functions," which make life easier for the database programmer. A chapter on using "system catalogs" (tables that describe the database itself) shows you how to obtain descriptions of tables, list what tables exist in the database and describe existing indexes are useful to understanding the database environment and orienting yourself within the database. I use these commands on a daily basis and it has become my habit to issue a "show tables" command on logging in just to jog my memory. I have to admit the "enterprise" orientation of the Practical SQL series can sometimes be distracting, expecting the reader will rarely be working directly with advanced query formulation or have access to system-level functions. This is atypical for the database programmer working on small business or non-profit websites where they have full access to the SQL server. Rarely will they generating simple reports and often are tasked with crafting complex queries by hand. Oddly, this make the companion edition more appropriate for the programmer, because they will often face dirty data or legacy code working on websites. Do not expect this book to teach you how to create database driven website applications. There are other books that delve into database programming. I trust the Practical SQL books for clear explanations of complicated SQL concepts in plain language tempered by common sense and practicality, not specific solutions.
Excellent!
Rating:
5 / 5
Smart, well reasoned, and covered what I needed.Excellent book, I development multimedia software, and use SQL, for my programs, easy to read, form mystery to mastery! this book is my head book!
A great sequel
Rating:
4 / 5
Unlike many Hollywood works, this sequel to the Practical SQL Handbook (that I have also reviewed here) manages to improve upon the previous title.The title of this work, with its pun (SQL/Sequel), is a great indicator that Bowman can write about a potentially dry topic while interjecting many grins throughout. I really appreciated that touch. One feature of this work that I especially liked is that it is organized by problem type (Managing Multiples) rather than by syntax (SELECT). This, in my opinion, is key to a book with the word 'Practical' in the title. Overall the presentation (layout, font, figures, etc.) is somewhat mundane; however, this does not take away from quality of the work. The sequel also includes a CD with an evaluation copy of Sybase Adaptive Server Anware and a working database, ready for you to use in working through the problems and solutions presented. Unlike many technical works, I found no errors in the problems or solutions presented. The sequel includes chapters on: - Handling Dirty Data - Translating Values - Managing Multiples - Navigating Numbers - Tuning Queries - Using SQL to Write SQL - Understanding the Sample Database - Comparing Data Type and Functions - Using Resources. Another feature that I enjoy is the fact that while the work presents standard SQL information, Bowman includes DBMS-specific variations (Sybase Adaptive Server, Sybase Adaptive Server Enterprise, MS SQL Server, Oracle, and Informix), albeit without includin one major DBMS, DB2. The missing DBMS is the reason I rate this work a 4 instead of a 5. I recommend this work to those that work with SQL or databases in general.
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