A Syntax Diagrams Syntax diagrams are drawings that illustrate valid SQL syntax. To read a diagram, trace it from left to right, in the direction shown by the arrows. Type them exactly as shown in the rectangles.
Parameters appear in lowercase inside ovals.
Variables are used for the parameters. Operators, delimiters, and terminators appear inside circles. If the syntax diagram has more than one path, you can choose any path to travel. If you have the choice of more than one keyword, operator, or parameter, your options appear in a vertical list. Required Keywords and Parameters Required keywords and parameters can appear singly or in a vertical list of alternatives.