MySQL Stored Procedure Programming

MySQL may be the most popular open source relational database management system (RDBMS) in the world, but during the first decade of its existence, it lacked support for stored programs, i.e., store procedures, functions, and triggers. The major commercial RDBMS vendors — including Oracle, IBM, and Microsoft — could point to this deficiency as reason enough to choose their proprietary systems over MySQL or any other open source system, such as PostgreSQL. But with the release of MySQL version 5.0, in October 2005, the "little database engine that could" dramatically improved its position against the competition. The most comprehensive discussion of these new capabilities is in the book MySQL Stored Procedure Programming.

Written by Guy Harrison and Steven Feuerstein, and published by O'Reilly Media on 28 March 2006 under the ISBN 978-0596100896, this book is the first one to offer database programmers a full discussion of the syntax, usage, and optimization of MySQL stored procedures, stored functions, and triggers — which the authors wisely refer to collectively as "stored programs", to simplify the manuscript. Even a year after the introduction of these new capabilities in MySQL, they have received remarkably little coverage by book publishers. Admittedly, there are three such chapters in MySQL Administrator's Guide and Language Reference (2nd Edition), written by some of the developers of MySQL, and published by MySQL Press. Yet this latter book — even though published a month after O'Reilly's — devotes fewer than 50 pages to stored programs, and the material is not in the printed book itself, but in the "MySQL Language Reference" part, on the accompanying CD. That material, in conjunction with the online reference documentation, may be sufficient for the more simple stored program development needs. But for any MySQL developer who wishes to understand in-depth how to make the most of this new functionality in version 5.0, they will likely need a much more substantial treatment — and that's exactly what Harrison and Feuerstein have created.

The authors are generous in both the technical information and development advice that they offer. The book's material spans 636 pages, organized into 23 chapters, grouped into four parts, followed by an index. The first part, "Stored Programming Fundamentals", provides an introduction and then a tutorial, both taking a broad view of MySQL stored programs. The remaining four chapters cover language fundamentals; blocks, conditional statements, and iterative programming; SQL; and error handling. The book's second part, "Stored Program Construction", may be considered the heart of the book, because its five chapters present the details of creating stored programs in general, using transaction management, using MySQL's built-in functions, and creating one's own stored functions, as well as triggers. The third part, "Using MySQL Stored Programs and Applications", explains some of the advantages and disadvantages of stored programs, and then illustrates how to call those stored programs from source code written in any one of five different programming languages: PHP, Java, Perl, Python, and Microsoft.NET. In the fourth and final part, "Optimizing Stored Programs", the authors focus on the security and tuning of stored programs, tuning SQL, optimizing the code, and optimizing the development process itself.

This is a substantial book, encompassing a great deal of technical as well as advisory information. Consequently, no review such as this can hope to describe or critically comment upon every section of every chapter of every part. Yet the overall quality and utility of the manuscript can be discerned simply by choosing just one of the aforesaid Web programming languages, and writing some code in that language to call some MySQL stored procedures and functions, to get results from a test database — and developing all of this code while relying solely upon the book under review. Creating some simple stored procedures, and calling them from some PHP and Perl scripts, demonstrated to me that MySQL Stored Procedure Programming contains more than enough coverage of the topics to be an invaluable guide in developing the most common functionality that a programmer would need to implement.

The book appears to have very few aspects or specific sections in need of improvement. The discussion of variable scoping, in Chapter 4, is too cursory (no database pun intended). In terms of the book's sample code, I found countless cases of inconsistency of formatting — specifically, operators such as "||" and "=" being jammed up against their adjacent elements, without any whitespace to improve readability. These minor flaws could be easily remedied in the next edition. Some programming books make similar mistakes, but throughout their text, which is even worse. Fortunately, most of the code in this book is neatly formatted, and the variable and program names are generally descriptive enough.

Some of the book's material could have been left out without great loss — thereby reducing the book's size, weight, and presumably price. The two chapters on basic and advanced SQL tuning contain techniques and recommendations covered with equal skill in other MySQL books, and were not needed in this one. On the other hand, sloppy developers who churn out lamentable code might argue that the last chapter, which focuses on best programming practices, could also be excised; but those are the very individuals who need those recommendations the most.

Fortunately, the few weaknesses in the book are completely overwhelmed by its positive qualities, of which there are many. The coverage of the topics is quite extensive, but without the repetition often seen in many other technical books of this size. The explanations are written with clarity, and provide enough detail for any experienced database programmer to understand the general concepts, as well as the specific details. The sample code effectively illustrates the ideas presented in the narration. The font, layout, organization, and fold-flat binding of this book, all make it a joy to read — as is characteristic of many of O'Reilly's titles.

Moreover, any programming book that manages to lighten the load of the reader by offering a touch of humor here and there, cannot be all bad. Steven Feuerstein is the author of several well-regarded books on Oracle, and it was nice to see him poke some fun at the database heavyweight, in his choice of sample code to demonstrate the my_replace() function: my_replace( 'We love the Oracle server', 'Oracle', 'MySQL' ).

The prospective reader who would like to learn more about this book, can consult its Web page on O'Reilly's site. There they will find both short and full descriptions, confirmed and unconfirmed errata, a link for writing a reader review, an online table of contents and index, and a sample chapter (number 6, "Error Handling"), in PDF format. In addition, the visitor can download all of the sample code in the book (562 files) and the sample database, as a mysqldump file.

Overall, MySQL Stored Procedure Programming is adeptly written, neatly organized, and exhaustive in its coverage of the topics. It is and likely will remain the premier printed resource for Web and database developers who want to learn how to create and optimize stored procedures, functions, and triggers within MySQL.