The Practical SQL Handbook: Using SQL Variants (4th Edition) by Judith S. Bowman

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 at a strong and steady rate. When we wrote the first edition of The 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 keeps a wary eye on what the others are doing and makes core offerings similar enough to attract both customers migrating from competitors, as well as new users looking for database systems they can 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.