The terminal elements are in capital letters, non-terminal in lowercase. The value of the terminal elements (between quotes) is a Python regular expression.
statement ::= (select | delete | insert | update) ';'
# select specific rules
select ::= 'DISTINCT'? E_TYPE selected_terms restriction? group? sort?
selected_terms ::= expression ( ',' expression)*
group ::= 'GROUPBY' VARIABLE ( ',' VARIABLE)*
sort ::= 'ORDERBY' sort_term ( ',' sort_term)*
sort_term ::= VARIABLE sort_method =?
sort_method ::= 'ASC' | 'DESC'
# delete specific rules
delete ::= 'DELETE' (variables_declaration | relations_declaration) restriction?
# insert specific rules
insert ::= 'INSERT' variables_declaration ( ':' relations_declaration)? restriction?
# update specific rules
update ::= 'SET' relations_declaration restriction
# common rules
variables_declaration ::= E_TYPE VARIABLE (',' E_TYPE VARIABLE)*
relations_declaration ::= simple_relation (',' simple_relation)*
simple_relation ::= VARIABLE R_TYPE expression
restriction ::= 'WHERE' relations
relations ::= relation (LOGIC_OP relation)*
| '(' relations')'
relation ::= 'NOT'? VARIABLE R_TYPE COMP_OP? expression
| 'NOT'? R_TYPE VARIABLE 'IN' '(' expression (',' expression)* ')'
expression ::= var_or_func_or_const (MATH_OP var_or_func_or_const) *
| '(' expression ')'
var_or_func_or_const ::= VARIABLE | function | constant
function ::= FUNCTION '(' expression ( ',' expression) * ')'
constant ::= KEYWORD | STRING | FLOAT | INT
# tokens
LOGIC_OP ::= ',' | 'OR' | 'AND'
MATH_OP ::= '+' | '-' | '/' | '*'
COMP_OP ::= '>' | '>=' | '=' | '<=' | '<' | '~=' | 'LIKE'
FUNCTION ::= 'MIN' | 'MAX' | 'SUM' | 'AVG' | 'COUNT' | 'UPPER' | 'LOWER'
VARIABLE ::= '[A-Z][A-Z0-9]*'
E_TYPE ::= '[A-Z]\w*'
R_TYPE ::= '[a-z_]+'
KEYWORD ::= 'TRUE' | 'FALSE' | 'NULL' | 'TODAY' | 'NOW'
STRING ::= "'([^'\]|\\.)*'" |'"([^\"]|\\.)*\"'
FLOAT ::= '\d+\.\d*'
INT ::= '\d+'
The tree research does not contain the selected variables (e.g. there is only what follows “WHERE”).
The insertion tree does not contain the variables inserted or relations defined on these variables (e.g. there is only what follows “WHERE”).
The removal tree does not contain the deleted variables and relations (e.g. there is only what follows the “WHERE”).
The update tree does not contain the variables and relations updated (e.g. there is only what follows the “WHERE”).
Select ((Relationship | And | Or)?, Group?, Sort?)
Insert (Relations | And | Or)?
Delete (Relationship | And | Or)?
Update (Relations | And | Or)?
And ((Relationship | And | Or), (Relationship | And | Or))
Or ((Relationship | And | Or), (Relationship | And | Or))
Relationship ((VariableRef, Comparison))
Comparison ((Function | MathExpression | Keyword | Constant | VariableRef) +)
Function (())
MathExpression ((MathExpression | Keyword | Constant | VariableRef), (MathExpression | Keyword | Constant | VariableRef))
Group (VariableRef +)
Sort (SortTerm +)
SortTerm (VariableRef +)
VariableRef ()
Variable ()
Keyword ()
Constant ()
It would be convenient to express the schema matching relations (non-recursive rules):
Document class Type <-> Document occurence_of Fiche class Type
Sheet class Type <-> Form collection Collection class Type
Therefore 1. becomes:
Document X where
X class C, C name 'Cartoon'
X owned_by U, U login 'syt'
X available true
I’m not sure that we should handle this at RQL level ...
There should also be a special relation ‘anonymous’.