The Practical SQL Handbook Using SQL Variants

This latest edition of the best-selling implementation guide to the Structured Query Language teaches SQL fundamentals while providing practical solutions for critical business applications. The Practical SQL Handbook, Fourth Editionnow includes expanded platform SQL coverage and extensive real-world examples based on feedback from actual SQL users. The Practical SQL Handbookbegins with a step-by-step introduction to SQL basics and examines the issues involved in designing SQL-based database applications. It fully explores SQL's most popular implementations from industry leaders, Oracle, Microsoft, Sybase, and Informix. Highlights include: Detailed coverage of SQL commands for creating databases, tables, and indexes, and for adding, changing, and deleting data Using the SELECT command to retrieve specific data Handling NULL values (missing information) in a relational database Joining tables, including self joins and outer joins (ANSI and WHERE-clause syntax) Working with nested queries (subqueries) to get data from multiple tables Creating views (virtual tables) to provide customized access to data Using SQL functions A bonus CD-ROM contains a time-limited, full-feature version of the Sybase® Adaptive Server Anywhere™ software as well as the sample database, scripts, and examples included in the book. The Practical SQL Handbookis the most complete reference available for day-to-day SQL implementations. 0201703092B05222001

Why New Editions? Many things have changed since this book was first published in 1989, and SQL is no exception. The SQL language has expanded tremendously, both in numbers of users and in numbers of commands. Sales of relational databases continue to rise at a strong and steady rate. When we wrote the first edition ofThe Practical SQL Handbook,the American National Standards Institute (ANSI) had already approved the 1986 SQL standard. The International Standards Organization (ISO) adopted it in 1987. Both ANSI and ISO helped create the 1989 version. The 1986 standards were skimpy, lacking features that most commercial vendors offered. The 1989 standards were more complete but still left many important elements undefined. For the first edition, we felt we should focus on industry practice: As always, each vendor was keeping a wary eye on what the others were doing and making core offerings similar enough to attract both customers migrating from competitors, as well as new users looking for database systems they could build on. Because of this, we left both the not-quite-jelled ANSI standards and particular vendor implementations to the experts in those fields and concentrated on the common ground: generic or "industry-practice" SQL. Our goal was to offer the intelligent amateur practical information on how to use the actually available SQL of that time. The 1992 ANSI standard (often called SQL-2 or SQL-92) represented a new stage in SQL development. This standard was more comprehensive than the 1989 standard: In written form it contained more than four times as many pages as the earlier version. Database vendors have adopted large parts of the 1992 standard. With the widespread adoption of the SQL-92 standard, the industry practice and the ANSI/ISO standards began to converge. Despite vendor-specific differences, there is a general, industrywide core of SQL commands that all users need to understand. Adopting standards doesn't happen overnight; it is a long process. At any point, vendors will have varying levels of conformance and will continue to produce vendor-specific variations. This book aims to give SQL users a mastery of the fundamentals of the language, with a side glance at the specifics of particular implementations. Changes for Recent Editions The changes for recent editions have been threefold: To include more real-world examples To emphasize the SQL-92 features that most vendors have imple-mented To provide software for hands-on practice Include More Real-World Examples In talking to new and developing SQL users, we heard over and over of their need for more examples to follow, change, narrow, and broaden. Accordingly, the bulk of the added material in the second edition consisted of code "recipes." Chapter 11, Solving Business Problems, is a selection of code samples based on questions and answers that came over computer newsgroups. We reproduce interesting problems and solutions in terms of the sample bookbiz database used throughout the book. The chapter includes examples of using the CASE function for conditional logic, formatting results, and finding date data. A few samples fall into a different category. They aren't so much solutions to problems as indications of common errors. They include issues with DISTINCT and misunderstandings of what SQL can do. Emphasize SQL-92 With the third edition, we revised the book to incorporate the SQL-92 features that most vendors had adopted. These include new datatypes, additions to the CREATE TABLE statement that allow built-in integrity constraints, modifications to the ORDER BY and GROUP BY clauses, the new escape cha