This chapter is the heart of SQL in a Nutshell: it is an alphabetical listing of SQL commands with detailed explanations and examples. Each command and function is identified in a master table as being “supported,” “supported with variations,” “supported with limitations,” or “not supported,” for each of the four SQL dialects covered in this book: SQL Server, MySQL, Oracle, and PostgreSQL. After a brief description of the SQL99 standard, each vendor application is discussed briefly but thoroughly, with supporting examples and sample coding.
When researching a command in this chapter, first read the introductory paragraph, vendor support table, and the section on SQL99 syntax and description. The reason for this is that any common features between all the implementations of the command are discussed once under the SQL99 topic. Thus, reading directly about a vendor’s implementation of a particular command may not describe every aspect of that command, since some of its details may be covered in the opening comments.