Syntax diagrams

The following rules apply to the syntax diagrams used in this information:

• Read the syntax diagrams from left to right, and from top to bottom, following the path of the line.

  The symbol indicates the beginning of a statement.

  The symbol indicates that the statement syntax is continued on the next line.

  The symbol indicates that a statement is continued from the previous line.

  The symbol indicates the end of a statement.

  Diagrams of syntactical units other than complete statements start with the symbol and end with the symbol.

• Required items appear on the horizontal line (the 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.

• An arrow returning to the left, above the main line, indicates an item that can be repeated.
  
  
  

  If the repeat arrow contains a comma, you must separate repeated items with a comma.

  
  
  

  A repeat arrow above a stack indicates that you can repeat the items in the stack.

• Keywords appear in uppercase (for example, FROM). They must be spelled exactly as shown. Variables appear in all lowercase letters (for example, column-name). They represent user-supplied names or values.
• If punctuation marks, parentheses, arithmetic operators, or other such symbols are shown, you must enter them as part of the syntax.