EJB query: BNF syntax

The Backus-Naur Form (BNF) is one of the most commonly used notations for specifying the syntax of programming languages or command sets. This article lists the syntax for EJBs query language.

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 } ]*

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Related concepts

EJB query language

 

Related tasks

Use EJB query