Query EJB: sintassi BNF

EJB QL ::= [select_clause] from_clause [where_clause] [order_by_clause]

DYNAMIC EJB QL := query_expression  [order_by_clause]  

query_expression := query_term [UNION [ALL] query_term]*

query_term :=  {select_clause_dynamic  from_clause  [where_clause] 
	[group_by_clause] [having_clause] } | (query_expression) }  [order_by_clause]


from_clause::=FROM identification_variable_declaration 
               [, {identification_variable_declaration | collection_member_declaration } ]*

identification_variable_declaration::=collection_member_declaration |
       range_variable_declaration [join]*

join :=  [ { LEFT [OUTER] | INNER  }]  JOIN  {collection_valued_path_expression | single_valued_path_expression}
 [AS] identifier

collection_member_declaration::=
       IN ( collection_valued_path_expression ) [AS] identifier

range_variable_declaration::=abstract_schema_name [AS] identifier

single_valued_path_expression ::=
       {single_valued_navigation | identification_variable}. ( cmp_field |  	
	method  |  cmp_field.value_object_attribute |  cmp_field.value_object_method )
          | single_valued_navigation

single_valued_navigation::=
       identification_variable.[  single_valued_cmr_field.  ]* 
            single_valued_cmr_field  

collection_valued_path_expression ::=
       identification_variable.[  single_valued_cmr_field.  ]* 
           collection_valued_cmr_field

select_clause::= SELECT { ALL | DISTINCT }  {single_valued_path_expression |
                         identification_variable |  OBJECT ( identification_variable) |
	       aggregate_functions } 

select_clause_dynamic ::= SELECT { ALL | DISTINCT }  [ selection , ]*  selection 

selection  ::= { expression  |  subselect }  [[AS] id ]

order_by_clause::= ORDER BY [ {single_valued_path_expression | integer}  [ASC|DESC],]*
      {single_valued_path_expression | integer}[ASC|DESC]

where_clause::= WHERE conditional_expression

conditional_expression ::= conditional_term | 
                           conditional_expression OR conditional_term
conditional_term ::= conditional_factor | 
                     conditional_term AND conditional_factor
conditional_factor ::= [NOT] conditional_primary
conditional_primary::=simple_cond_expression | (conditional_expression)

simple_cond_expression ::= comparison_expression | between_expression | 
       like_expression | in_expression | null_comparison_expression |
       empty_collection_comparison_expression | quantified_expression |
       exists_expression | is_of_type_expression  |  collection_member_expression

between_expression ::= expression [NOT] BETWEEN expression AND expression

in_expression ::= single_valued_path_expression [NOT] IN 
           { (subselect) |  ( [ atom ,]* atom )  }

atom = { string-literal | numeric-constant | input-parameter }
                
like_expression ::= expression [NOT] LIKE 
                {string_literal | input_parameter} 
                [ESCAPE {string_literal | input_parameter}]

null_comparison_expression ::= 
       single_valued_path_expression IS [ NOT ] NULL 

empty_collection_comparison_expression ::=
       collection_valued_path_expression IS [NOT] EMPTY

collection_member_expression  ::=
       { single_valued_path_expression |  input_paramter }  [ NOT ] MEMBER [ OF ] 
         collection_valued_path_expression

quantified_expression ::=
       expression comparison_operator  {SOME | ANY | ALL} (subselect)

exists_expression ::= EXISTS {collection_valued_path_expression |  (subselect)}

subselect ::= SELECT [{ ALL | DISTINCT }]  expression  from_clause [where_clause] 
       [group_by_clause] [having_clause]

group_by_clause::= GROUP BY [single_valued_path_expression,]*
                    single_valued_path_expression

having_clause ::= HAVING conditional_expression


is_of_type_expression ::= identifier  IS OF TYPE
            ([[ONLY] abstract_schema_name,]* [ONLY] abstract_schema_name)  

comparison_expression ::=  expression   comparison_operator { expression |  ( subquery ) }

comparison_operator ::=    = | > | >= | < | <= | <> 

method ::=  method_name( [[expression , ]* expression ] )    

expression ::= term |   expression {+|-} term 

term ::=  factor |  term {*|/} factor

factor ::= {+|-} primary

primary ::= single_valued_path_expression | literal |
       ( expression ) |  input_parameter | functions | aggregate_functions

aggregate_functions := 
       AVG([ALL|DISTINCT] expression) |
       COUNT({[ALL|DISTINCT] expression | * | identification_variable }) |
       MAX([ALL|DISTINCT] expression) |
       MIN([ALL|DISTINCT] expression) |
       SUM([ALL|DISTINCT] expression) |

functions ::= 
        ABS(expression) | 
        BIGINT(expression) |
        CHAR({expression [,{ISO|USA|EUR|JIS}] )  |
        CONCAT (expression , expression ) |
        DATE(expression) |
        DAY({expression ) |
        DAYS( expression) |
        DECIMAL( expression [,integer[,integer]])
        DIGITS( expression) |
        DOUBLE( expression ) |
        FLOAT( expression) |
        HOUR ( expression ) |
        INTEGER( expression ) |
        LCASE ( expression) |
        LENGTH(expression) |
        LOCATE( expression, expression [, expression] ) |
        MICROSECOND( expression ) |
        MINUTE ( expression ) |
        MOD ( expression , expression ) |
        MONTH( expression ) |
        REAL( expression) |
        SECOND( expression ) |
        SMALLINT( expression )  |
        SQRT (  expression) |
        SUBSTRING( expression, expression[, expression]) |
        TIME( expression ) |
        TIMESTAMP( expression ) |
        UCASE ( expression) |
        YEAR( expression )

xrel := XREL identification_variable . { single_valued_cmr_field | collection_valued_cmr_field }
	            [ , identification_variable . { single_valued_cmr_field | collection_valued_cmr_field } ]*