This appendix describes the notation conventions in this book.
This book uses three conventions to describe the SQL syntax and code:
Syntax diagrams describe SQL syntax form, including options. See “Syntax Diagram Conventions.”
Square braces in the text represent options. The indicated parentheses are required
when you specify options.
For example:
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 represents unprintable Japanese characters.
See “Character Shorthand Notation Used In This Book” on page 654.