How to read syntax diagrams
The rules in this section apply to the syntax diagrams that are used in this publication.
- Arrow symbols
- Read the syntax diagrams from left to right, from top to bottom,
following the path of the line.
- ►►───
- Two right arrows followed by a line indicate the beginning of a statement.
- ───►
- One right arrow at the end of a line indicates that the statement syntax is continued on the next line.
- ►───
- One right arrow followed by a line indicates that a statement is continued from the previous line.
- ───►◄
- A line followed by a right arrow and a left error indicates the end of a statement.
- Conventions
-
- SQL commands appear in uppercase.
- Variables appear in italics (for example, column-name). They represent user-defined parameters or suboptions.
- When entering commands, separate parameters and keywords by at least one blank if there is no intervening punctuation.
- Enter punctuation marks (slashes, commas, periods, parentheses, quotation marks, equal signs) and numbers exactly as given.
- Footnotes are shown by a number in parentheses, for example, (1).
- Required items
- Required items appear on the horizontal line (the main path).
- Optional items
- Optional items appear below the main path.
If an optional item appears above the main path, that item has no effect on the execution of the statement and is used only for readability.
- Multiple required or optional items
- If you can choose from two or more items, they appear vertically in a stack. If you must choose one of the items, one item of the stack appears on the stack main path.
- Repeatable items
- An arrow returning to the left above the main line indicates that
an item can be repeated.
If the repeat arrow contains a comma, you must separate repeated items with a comma.
If the repeat arrow contains a number in parenthesis, the number represents the maximum number of times that the item can be repeated.
A repeat arrow above a stack indicates that you can specify more than one of the choices in the stack.
- Default keywords
- IBM®-supplied default keywords appear above the main path, and the remaining choices are shown below the main path. In the parameter list following the syntax diagram, the default choices are underlined.
