SQL (Structured Query Language) is a standardized query language for requesting information from a database. Historically, SQL has been the choice for database management systems running on minicomputers and mainframes. Increasingly, however, SQL is being adapted to PC database systems because it supports distributed databases - databases that are spread out over several computer systems, so that several users on a local-area network can access the same database simultaneously. Although there are different dialects of SQL, it is the closest thing to a standard query language that currently exists. SQL in a Nutshell is a practical command reference to the Structured Query Language (SQL99), helping readers learn how their favourite database product supports any standard SQL command. This book presents each of the SQL commands and describes its use in both commercial (Microsoft SQL Server 2000 and Oracle 8i) and open source (MySQL, PostgreSQL 7.0) implementations. Each command reference includes the command syntax (by vendor, if the syntax differs across implementations), a description, and informative examples that illustrate important concepts and uses. SQL in a Nutshell is more than a reference guide for experienced SQL programmers, analysts, and database administrators. It also aims to provide a learning resource for novice and auxiliary SQL users such as system administrators, users of packaged client/server products, and consultants who need to be familiar with the various SQL dialects across many platforms.