Document Conventions

The syntax uses building blocks that are called productions. Productions are denoted by the symbol ::= . To the left of the equal sign is a production name; to the right of the equal, or on the next line, is a list of production constructs. If a production has more than one possible construct, the alternatives are separated by a vertical bar |. Read productions top-down. For example, reading the delete statement, there are literal keywords and two subproductions, a table specification and the WHERE clause.

Subproductions that are referenced within a production definition are HTML links to their definitions. You can navigate the links with an HTML browser.

Traversing down a syntax tree leads to leaf or terminal definitions. The definitions are composed either of keywords (select), identifiers (names of tables, columns, and so on) or symbols ( punctuation, operators, and so on.). Keywords and identifiers are shown with bold, capitalized text. In contrast, symbols are shown with single quotation marks and are bold.

Optional syntax is delimited by square brackets, [ and ]. Optional lists (syntax elements that are repeated) are denoted by [ and ]*. The * signifies zero or more occurrences of the bracketed syntax.

Selection lists, that allow you to choose from a list of alternative syntax elements, are denoted by braces { and }. These elements are separated by a vertical bar |. The selection list itself is not optional; you must choose at least one element. If you must choose one or more of the elements, the list is terminated with a }+. The + indicates one or more occurrences of the delimited syntax.