How to read the syntax diagrams
Syntax described using diagrams.
Throughout this section, syntax is described using diagrams such as the one shown here, which describes the RECOVER command:
The symbols used in syntax diagrams have this meaning:
- ►►─────
- The statement begins here.
- ──────►
- The statement is continued on the next line.
- ►──────
- The statement is continued from a previous line.
- ─────►◄
- The statement ends here.
These are the conventions used in the diagrams:
- Required items appear on the horizontal line (main path):
- Optional items appear below the main path:
- 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 main path.
If choosing one of the items is optional, the entire stack appears below the main path.
- Keywords that are above the main line are default keywords.
- An arrow returning to the left above the item shows an item that you can
repeat. Required items appear on the main line and optional items appear below
the main line.
A repeat arrow shows that you can make more than one choice from the stacked items, or repeat a single item. If a separator is required between items, it is shown as a comma in the repeat arrow.
- Keywords appear in uppercase; for example,
STATEMENT
). - Parentheses and commas must be entered as part of the command syntax as shown.