Syntax Diagram for Query Language Constructions

The query language syntax is described using a set of rules. Each rule normally describes one language construction.
Each language construction can contain keywords, separators (periods, commas, parentheses), and other language constructions.

Example:

<Language construction>
THIS_IS_KEYWORD
<This is language construction>, <This is language construction>
THIS_IS_FUNCTION ( <This is language construction> )

In the rules describing query language, language constructions are indicated within angle brackets. Keywords and function names are written in capital letters.

Language constructions can contain optional items, e.g. keywords and others. The rules describing query language indicate optional items in square brackets "[" and "]":

[THIS_IS_OPTIONAL_WORD]
[<This is optional construction>]

In some cases, alternative items can be used in a language construction. Such items are separated by the vertical stroke ("|"):

THIS_WORD | OR_THIS_WORD
<Either this construction> | <Or this construction>

Descriptions of all constructions include examples explaining the procedures of use in the query language.