U-SQL Syntax Conventions (U-SQL)


This document uses an Extended Backus-Naur syntax notation of the following structure:

Each syntax grammar rule has a name followed by the rule body, as in:

name := rule.  

Each rule body is either a reference to a name or a composition of the following rule expressions recursively. The following table lists and describes conventions that are used in the syntax diagrams in the U-SQL Language Reference.

Convention Used for
[rule] Brakets indicate that the grammar rule rule occurs either 0 or 1 times. Do not type the brackets.
{rule} Curly braces indicate that the grammar rule rule occurs 0 to n times. Do not type the braces.
(rule) Parenthesis are used to nest and group grammar rules. Do not type the parenthesis.
rule1 | rule2 The vertical line represents a choice between rule1 or rule2. It binds weaker than any of the other grammar rules. You can use only one of the items.
'abc' Literal keyword abc.
'abc'+rule Literal prefix abc tied to result of grammar rule rule without optional whitespace.
; U-SQL statement terminator.

Upper-case rule names inside a rule definition are defined in the language reference documentation. Lower-case rule names are considered self-evident and not further specified.

See Also