This appendix describes the notation conventions used in this book.
Throughout this book, three conventions are used to describe the SQL syntax and code:
Syntax diagrams, used to describe SQL syntax form, including options. See “Syntax Diagram Conventions” on page 341.
Square braces in the text, used to represent options. The indicated parentheses are
required when you specify options.
DECIMAL [(n[,m])] means the decimal data type can be defined optionally:
without specifying the precision
value n or scale value m
specifying precision (n) only
specifying both values (n,m)
you cannot specify scale without first defining precision.
CHARACTER [(n)] means that use of (n) is optional.
The values for n and m are integers in all cases
Japanese character code shorthand notation, used to represent unprintable Japanese
characters. See “Character Shorthand Notation Used In This Book” on page 346.
Symbols from the predicate calculus are also used occasionally to describe logical
operations. See “Predicate Calculus Notation Used In This Book” on page 348.