Certain typographical conventions are used in this manual to clarify the meaning and usage of various commands, statements, programs, examples, etc. This section provides a summary of these conventions.
In the following descriptions a term refers to any word or group of words which may be language keywords, user-supplied values, literals, etc. A term’s exact meaning depends upon the context in which it is used.
● Italic font introduces a new term, typically, in the sentence that defines it for the first time.
● Fixed-width (mono-spaced) font is used for terms that must be given literally such as SQL commands, specific table and column names used in the examples, programming language keywords, etc. For example, SELECT * FROM emp;
● Italic fixed-width font is used for terms for which the user must substitute values in actual usage. For example, DELETE FROM table_name;
● A vertical pipe | denotes a choice between the terms on either side of the pipe. A vertical pipe is used to separate two or more alternative terms within square brackets (optional choices) or braces (one mandatory choice).
● Square brackets [ ] denote that one or none of the enclosed term(s) may be substituted. For example, [ a | b ], means choose one of “a” or “b” or neither of the two.
● Braces {} denote that exactly one of the enclosed alternatives must be specified. For example, { a | b }, means exactly one of “a” or “b” must be specified.
● Ellipses ... denote that the proceeding term may be repeated. For example, [ a | b ] ... means that you may have the sequence, “b a a b a”.
