org.eclipse.persistence.jpa.jpql.parser

Class RangeVariableDeclaration

java.lang.Object

org.eclipse.persistence.jpa.jpql.parser.AbstractExpression

org.eclipse.persistence.jpa.jpql.parser.RangeVariableDeclaration

All Implemented Interfaces:

Expression

public final class RangeVariableDeclaration
extends AbstractExpression

Range variable declarations allow the developer to designate a "root" for objects which may not be reachable by navigation. In order to select values by comparing more than one instance of an entity abstract schema type, more than one identification variable ranging over the abstract schema type is needed in the FROM clause.

JPA:

BNF: range_variable_declaration ::= abstract_schema_name [AS] identification_variable

EclipseLink 2.4:

BNF: range_variable_declaration ::= { root_object } [AS] identification_variable

BNF: root_object ::= abstract_schema_name | (subquery)

Since:

2.3

Version:

2.5

Author:

Pascal Filion

Field Summary

Fields inherited from class org.eclipse.persistence.jpa.jpql.parser.AbstractExpression

COMMA, DOT, DOUBLE_QUOTE, LEFT_CURLY_BRACKET, LEFT_PARENTHESIS, NOT_DEFINED, RIGHT_CURLY_BRACKET, RIGHT_PARENTHESIS, SINGLE_QUOTE, SPACE, UNDERSCORE

Fields inherited from interface org.eclipse.persistence.jpa.jpql.parser.Expression

ABS, ALL, AND, ANY, AS, AS_OF, ASC, AVG, BETWEEN, BIT_LENGTH, BOTH, CASE, CAST, CHAR_LENGTH, CHARACTER_LENGTH, CLASS, COALESCE, COLUMN, CONCAT, CONNECT_BY, COUNT, CURRENT_DATE, CURRENT_TIME, CURRENT_TIMESTAMP, DELETE, DELETE_FROM, DESC, DIFFERENT, DISTINCT, DIVISION, ELSE, EMPTY, END, ENTRY, EQUAL, ESCAPE, EXCEPT, EXISTS, EXTRACT, FALSE, FETCH, FIRST, FROM, FUNC, FUNCTION, GREATER_THAN, GREATER_THAN_OR_EQUAL, GROUP_BY, HAVING, IN, INDEX, INNER, INNER_JOIN, INNER_JOIN_FETCH, INTERSECT, IS, IS_EMPTY, IS_NOT_EMPTY, IS_NOT_NULL, IS_NULL, JOIN, JOIN_FETCH, KEY, LAST, LEADING, LEFT, LEFT_JOIN, LEFT_JOIN_FETCH, LEFT_OUTER_JOIN, LEFT_OUTER_JOIN_FETCH, LENGTH, LIKE, LOCATE, LOWER, LOWER_THAN, LOWER_THAN_OR_EQUAL, MAX, MEMBER, MEMBER_OF, MIN, MINUS, MOD, MULTIPLICATION, NAMED_PARAMETER, NEW, NOT, NOT_BETWEEN, NOT_EQUAL, NOT_EXISTS, NOT_IN, NOT_LIKE, NOT_MEMBER, NOT_MEMBER_OF, NULL, NULLIF, NULLS, NULLS_FIRST, NULLS_LAST, OBJECT, OF, ON, OPERATOR, OR, ORDER_BY, ORDER_SIBLINGS_BY, OUTER, PLUS, POSITION, POSITIONAL_PARAMETER, QUOTE, REGEXP, SCN, SELECT, SET, SIZE, SOME, SQL, SQRT, START_WITH, SUBSTRING, SUM, TABLE, THEN, TIMESTAMP, TRAILING, TREAT, TRIM, TRUE, TYPE, UNION, UNKNOWN, UPDATE, UPPER, VALUE, WHEN, WHERE

Constructor Summary

Constructors

Constructor and Description
RangeVariableDeclaration(AbstractExpression parent) Creates a new RangeVariableDeclaration.
RangeVariableDeclaration(java.lang.String entityName, java.lang.String variableName) Creates a new RangeVariableDeclaration, which is used as a virtual declaration.

Method Summary

Modifier and Type	Method and Description
void	accept(ExpressionVisitor visitor) Visits this Expression by the given visitor.
void	acceptChildren(ExpressionVisitor visitor) Visits the children of this Expression.
JPQLQueryBNF	findQueryBNF(Expression expression) Retrieves the JPQLQueryBNF that represents the fragment of this Expression that was used when parsing the given Expression.
java.lang.String	getActualAsIdentifier() Returns the actual AS found in the string representation of the JPQL query, which has the actual case that was used.
Expression	getIdentificationVariable() Returns the Expression that represents the identification variable.
JPQLQueryBNF	getQueryBNF() Returns the BNF of this Expression.
Expression	getRootObject() Returns the Expression that represents the "root" object.
boolean	hasAs() Determines whether the identifier AS was parsed.
boolean	hasIdentificationVariable() Determines whether the identification variable was parsed.
boolean	hasRootObject() Determines whether the "root" object was parsed.
boolean	hasSpaceAfterAs() Determines whether a whitespace was parsed after AS.
boolean	hasSpaceAfterRootObject() Determines whether a whitespace was parsed after the "root" object.
boolean	hasVirtualIdentificationVariable() Determines whether this identification variable is virtual, meaning it's not part of the query but is required for proper navigability.
void	setVirtualIdentificationVariable(java.lang.String variableName) Sets a virtual identification variable because the "root" object was parsed without one.
void	setVirtualIdentificationVariable(java.lang.String variableName, java.lang.String path) Sets a virtual identification variable to qualify the "root" object.

Methods inherited from class org.eclipse.persistence.jpa.jpql.parser.AbstractExpression

children, getGrammar, getIdentifierVersion, getLength, getOffset, getParent, getQueryBNF, getRoot, isAncestor, orderedChildren, populatePosition, toActualText, toParsedText, toString

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

RangeVariableDeclaration

public RangeVariableDeclaration(AbstractExpression parent)

Creates a new RangeVariableDeclaration.

Parameters:

parent - The parent of this expression

RangeVariableDeclaration

public RangeVariableDeclaration(java.lang.String entityName,
                                java.lang.String variableName)

Creates a new RangeVariableDeclaration, which is used as a virtual declaration.

Parameters:

entityName - The name of the entity to be accessible with the given variable name

variableName - The identification variable used to navigate to the entity

Method Detail

accept

public void accept(ExpressionVisitor visitor)

Visits this Expression by the given visitor.

Parameters:

visitor - The ExpressionVisitor to visit this object

acceptChildren

public void acceptChildren(ExpressionVisitor visitor)

Visits the children of this Expression. This method can be used to optimize traversing the children since a new list is not created every time Expression.children() is called.

This does not traverse the Expression sub-hierarchy, use a subclass of AbstractTraverseChildrenVisitor in order to traverse the entire sub-hierarchy.

Parameters:

visitor - The visitor to visit the children of this object.

findQueryBNF

public JPQLQueryBNF findQueryBNF(Expression expression)

Retrieves the JPQLQueryBNF that represents the fragment of this Expression that was used when parsing the given Expression.

Specified by:

findQueryBNF in interface Expression

Overrides:

findQueryBNF in class AbstractExpression

Parameters:

expression - The Expression that is a descendant of this one

Returns:

The JPQLQueryBNF that was used to parse the given expression

getActualAsIdentifier

public java.lang.String getActualAsIdentifier()

Returns the actual AS found in the string representation of the JPQL query, which has the actual case that was used.

Returns:

The AS identifier that was actually parsed, or an empty string if it was not parsed

getIdentificationVariable

public Expression getIdentificationVariable()

Returns the Expression that represents the identification variable.

Returns:

The expression that was parsed representing the identification variable

getQueryBNF

public JPQLQueryBNF getQueryBNF()

Returns the BNF of this Expression.

Returns:

The JPQLQueryBNF, which represents the grammar of this Expression

getRootObject

public Expression getRootObject()

Returns the Expression that represents the "root" object.

Returns:

The expression that was parsed representing the "root" object

hasAs

public boolean hasAs()

Determines whether the identifier AS was parsed.

Returns:

true if the identifier AS was parsed; false otherwise

hasIdentificationVariable

public boolean hasIdentificationVariable()

Determines whether the identification variable was parsed.

Returns:

true if the identification variable was parsed; false otherwise

hasRootObject

public boolean hasRootObject()

Determines whether the "root" object was parsed.

Returns:

true if the "root" object was parsed; false otherwise

hasSpaceAfterAs

public boolean hasSpaceAfterAs()

Determines whether a whitespace was parsed after AS.

Returns:

true if there was a whitespace after AS; false otherwise

hasSpaceAfterRootObject

public boolean hasSpaceAfterRootObject()

Determines whether a whitespace was parsed after the "root" object.

Returns:

true if there was a whitespace after "root" object; false otherwise

hasVirtualIdentificationVariable

public boolean hasVirtualIdentificationVariable()

Determines whether this identification variable is virtual, meaning it's not part of the query but is required for proper navigability.

Returns:

true if this identification variable was virtually created to fully qualify path expression; false if it was parsed

setVirtualIdentificationVariable

public void setVirtualIdentificationVariable(java.lang.String variableName)

Sets a virtual identification variable because the "root" object was parsed without one. This is valid in an UPDATE and DELETE queries. Example:

UPDATE DateTime SET date = CURRENT_DATE

is equivalent to

UPDATE DateTime d SET d.date = CURRENT_DATE

Parameters:

variableName - A virtual identification variable that will identify the "root" object

setVirtualIdentificationVariable

public void setVirtualIdentificationVariable(java.lang.String variableName,
                                             java.lang.String path)

Sets a virtual identification variable to qualify the "root" object. The "root" object is a derived path that does not start with an identification variable. Example:

UPDATE Employee SET firstName = 'MODIFIED' WHERE (SELECT COUNT(m) FROM managedEmployees m) > 0

'managedEmployees' is a derived path and will become qualified with the given virtual identification variable.

Parameters:

variableName - The identification variable that was generated to qualify the "root" object

path - The path that was parsed as a "root" object