Query Language Grammar

This topic describes the VMware Tanzu GemFire query language grammar.

Language Grammar

Notation used in the grammar: n
A nonterminal symbol that has to appear at some place within the grammar on the left side of a rule. All nonterminal symbols have to be derived to be terminal symbols.

t
A terminal symbol (shown in italic bold).

x y
x followed by y

x | y
x or y

(x | y)
x or y

[ x ]
x or empty

{ x }
A possibly empty sequence of x.

comment
descriptive text

Grammar list:

symbol ::= expression
query_program ::= [ imports semicolon ] query [semicolon]
imports ::= import { semicolon import }
import ::= IMPORT qualifiedName [ AS identifier ]
query ::= selectExpr | expr
selectExpr ::= SELECT DISTINCT projectionAttributes fromClause [ whereClause ]
projectionAttributes ::= * | projectionList
projectionList ::= projection { comma projection }
projection ::= field | expr [ AS identifier ]
field ::= identifier colon expr
fromClause ::= FROM iteratorDef { comma iteratorDef }
iteratorDef ::= expr [ [ AS ] identifier ] [ TYPE identifier ] | identifier IN expr [ TYPE identifier ]
whereClause ::= WHERE expr
expr ::= castExpr
castExpr ::= orExpr | left_paren identifier right_paren castExpr
orExpr ::= andExpr { OR andExpr }
andExpr ::= equalityExpr { AND equalityExpr }
equalityExpr ::= relationalExpr { ( = | <> | != ) relationalExpr }
relationalExpr ::= additiveExpr { ( < | <= | > | >= ) additiveExpr }
additiveExpr ::= multiplicativeExpr { (+ | -) multiplicativeExpr }
multiplicativeExpr ::= inExpr { (MOD | % | / | *) inExpr}
inExpr ::= unaryExpr { IN unaryExpr }
unaryExpr ::= [ NOT ] postfixExpr
postfixExpr ::= primaryExpr { left_bracket expr right_bracket }
       | primaryExpr { dot identifier [ argList ] }
argList ::= left_paren [ valueList ] right_paren
qualifiedName ::= identifier { dot identifier }
primaryExpr ::= functionExpr
       | identifier [ argList ]
       | undefinedExpr
       | collectionConstruction
       | queryParam
       | literal
       | ( query )
       | region_path
functionExpr ::= ELEMENT left_paren query right_paren
       | NVL left_paren query comma query right_paren
       | TO_DATE left_paren query right_paren
undefinedExpr ::= IS_UNDEFINED left_paren query right_paren
       | IS_DEFINED left_paren query right_paren
collectionConstruction ::= SET left_paren [ valueList ] right_paren
valueList ::= expr { comma expr }
queryParam ::= $ integerLiteral
region_path ::= forward_slash region_name { forward_slash region_name }
region_name ::= name_character { name_character }
identifier ::= letter { name_character }
literal ::= booleanLiteral
       | integerLiteral
       | longLiteral
       | doubleLiteral
       | floatLiteral
       | charLiteral
       | stringLiteral
       | dateLiteral
       | timeLiteral
       | timestampLiteral
       | NULL
       | UNDEFINED
booleanLiteral ::= TRUE | FALSE
integerLiteral ::= [ dash ] digit { digit }
longLiteral ::= integerLiteral L
floatLiteral ::= [ dash ] digit { digit } dot digit { digit } [ ( E | e ) [ plus | dash ] digit { digit } ] F
doubleLiteral ::= [ dash ] digit { digit } dot digit { digit } [ ( E | e ) [ plus | dash ] digit { digit } ] [ D ]
charLiteral ::= CHAR single_quote character single_quote
stringLiteral ::= single_quote { character } single_quote
dateLiteral ::= DATE single_quote integerLiteral dash integerLiteral dash integerLiteral single_quote
timeLiteral ::= TIME single_quote integerLiteral colon
       integerLiteral colon integerLiteral single_quote
timestampLiteral ::= TIMESTAMP single_quote
       integerLiteral dash integerLiteral dash integerLiteral integerLiteral colon
       integerLiteral colon
       digit { digit } [ dot digit { digit } ] single_quote
letter ::= any unicode letter
character ::= any unicode character except 0xFFFF
name_character ::= letter | digit | underscore
digit ::= any unicode digit

The expressions in the following are all terminal characters:

dot ::= .
left_paren ::= (
right_paren ::= )
left_bracket ::= [
right_bracket ::= ]
single_quote ::= '
underscore ::= _
forward_slash ::= /
comma ::= ,
semicolon ::= ;
colon ::= :
dash ::= -
plus ::= +
            

Language Notes

• Query language keywords such as SELECT, NULL, and DATE are case-insensitive. Identifiers such as attribute names, method names, and path expressions are case-sensitive.
• Comment lines begin with ‑‑ (double dash).
• Comment blocks begin with /* and end with */.

• String literals are delimited by single-quotes. Embedded single-quotes are doubled.

  Examples:

  'Hello' value = Hello
  'They said, ''Hello''' value = They said, 'Hello'
  

• Character literals begin with the CHAR keyword followed by the character in single quotation marks. The single-quotation mark character itself is represented as CHAR '''' (with four single quotation marks).

• In the TIMESTAMP literal, there is a maximum of nine digits after the decimal point.