|SQL: Visual QuickStart Guide|
|summary||A lucid SQL tutorial and professional reference|
What this book does right:The myth that it's more important for a programming book to be technically accurate than well written endures even though the opposite situation is true: A lucid explanation of a difficult concept or clever algorithm is more valuable than a bug-free implementation of same.
Consider Ken Henderson's The Guru's Guide to Transact-SQL , a book full of useful examples but so marred by the author's bloated style and disrespect for the language that I cringe every time I'm forced to read the text rather than simply lift a code snippet. Henderson even goes so far as to include an introductory section, titled "On Formality," about how he is going to split infinitives (even though their syntax is a burden for the brain to parse) and how he is going to use "data" in the singular sense (even though doing so can cause confusion) and how he considers "record," "row", and "tuple" to be interchangeable terms (even though they're not) and on and on. Readers would be aghast to find such self-exculpatory nonsense in the pages of Donald Knuth or Patrick Henry Winston. As for SQL: Visual QuickStart Guide, the author, a statistical programmer, presents each topic with a mathematician's sense of restraint and order. I've found few typos, no technical errors, and consistent use of technical terms.
Almost every aspect of SELECT, INSERT, UPDATE, DELETE, CREATE, ALTER, and DROP is covered. What distinguishes this book is that every ANSI SQL statement -- and there are hundreds of examples -- was tested on six separate DBMSes: Microsoft Access 2002, Microsoft SQL Server 2000, MySQL 4.0, PostgreSQL 7.1, Oracle 8i, and Oracle 9i (8i and 9i differ considerably in SQL-92 compliance). The examples in each section increase in depth and complexity, so you can stop reading once you've learned what you need to know. When an ANSI SQL statement doesn't work as-is on a particular DBMS, the author shows you how to fix it or offers workarounds (which is particularly useful for MySQL, whose adherence to the SQL standard is poor). These DBMS-specific fixes are given as separate "DBMS Tips" apart from the main body of text, so they don't interfere with the conceptual flow. This organization is especially useful for consultants who have difficulty keeping track of how each implementation deviates from the ANSI standard, and is superior to the alphabetical, segregated approach of O'Reilly's SQL in a Nutshell.
This book was shoehorned into the publisher's Visual QuickStart format, which, as I implied earlier, doesn't work well for procedural languages, but does work for a declarative language like SQL. A two-column layout separates examples from explanatory text. Red type highlights the relevant portions of code and results. The book is extensively cross-referenced and has an 18-page index. This layout also makes the book a good quick reference for experienced programmers. Almost all the examples use a single, sample database (so there's no need to memorize multiple schemas). The code listings and sample database are available for download.
The derivative nature of programming books makes it difficult to determine whether the author truly has mastered the material. Writing a book is a difficult task (perhaps even harder than programming) but, at the risk of exaggerating my point, I suspect that any determined, organized, and competent programmer could write any O'Reilly Nutshell book by paraphrasing existing materials. But if an author establishes his credentials early, the reader gains a sense of trust that remains throughout the entire book. In the introduction to this book, the author avoids an error that almost every other SQL-book author commits: that SQL stands for structured query language. According to ANSI (the only legitimate arbiter here), it stands for S-Q-L and nothing more. Fehily even offers an amusing explanation of why structured query language is the worst possible description of SQL. Throughout the book, the author also scatters bits of practical advice (job candidates are wise to say my-es-kyu-el, not my-sequel), beginner-friendly insights ("Although SELECT is powerful, it's not dangerous: You can't use it add, change, or delete data or database objects."), and advanced topics (optimization, concurrency control, logical data independence). It is these asides and respect for basic research, rather than swaths of expository text, that lend authority.
This book describes the effects of nulls in almost every aspect of SQL, including the interpretation of null-contaminated query results. You can no more be a competent SQL programmer without understanding nulls than you can be a competent LISP programmer without understanding recursion. Particularly useful are the discussion of three-value logic (true/false/unknown) and an algebraic derivation of how a null can cause a subquery to return an empty result unexpectedly (which has bitten me more than once).
As a wizened developer weary of hand-holding users and junior programmers through routine queries, I've found it mollifying to give away copies of this book (it's cheap) to reduce my interrupt stack.
What's Missing:Some missing items that I would have found useful:
- A glossary
- A quick syntax reference
- A chapter about statistics
- A chapter about advanced SQL "tricks"
- DB2 coverage
- Coverage of security commands (GRANT/REVOKE)
- An expanded query-optimization discussion
- Improved normalization examples
- A little more mathematical rigor in the set-theory discussion
You can purchase SQL: Visual QuickStart Guide from bn.com. Slashdot welcomes readers' book reviews -- to see your own review here, read the book review guidelines, then visit the submission page.