org.eclipse.persistence.jpa.internal.jpql.parser

Class Join

java.lang.Object

org.eclipse.persistence.jpa.internal.jpql.parser.StringExpression

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

org.eclipse.persistence.jpa.internal.jpql.parser.Join

All Implemented Interfaces:

Expression

public final class Join
extends AbstractExpression

A JOIN enables the fetching of an association as a side effect of the execution of a query. A JOIN is specified over an entity and its related entities.

BNF: join ::= join_spec join_association_path_expression [AS] identification_variable

Since:

2.3

Version:

2.3

Author:

Pascal Filion

Field Summary

Fields inherited from class org.eclipse.persistence.jpa.internal.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.internal.jpql.parser.Expression

ABS, ALL, AND, ANY, AS, ASC, AVG, BETWEEN, BIT_LENGTH, BOTH, CASE, CHAR_LENGTH, CHARACTER_LENGTH, CLASS, COALESCE, CONCAT, COUNT, CURRENT_DATE, CURRENT_TIME, CURRENT_TIMESTAMP, DELETE, DELETE_FROM, DESC, DIFFERENT, DISTINCT, DIVISION, ELSE, EMPTY, END, ENTRY, EQUAL, ESCAPE, EXISTS, FALSE, FETCH, FROM, FUNC, GREATER_THAN, GREATER_THAN_OR_EQUAL, GROUP_BY, HAVING, IN, INDEX, INNER, INNER_JOIN, INNER_JOIN_FETCH, IS, IS_EMPTY, IS_NOT_EMPTY, IS_NOT_NULL, IS_NULL, JOIN, JOIN_FETCH, KEY, 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_EXISTS, NOT_IN, NOT_LIKE, NOT_MEMBER, NOT_MEMBER_OF, NULL, NULLIF, OBJECT, OF, OR, ORDER_BY, OUTER, PLUS, POSITION, POSITIONAL_PARAMETER, QUOTE, SELECT, SET, SIZE, SOME, SQRT, SUBSTRING, SUM, THEN, TRAILING, TREAT, TRIM, TRUE, TYPE, UNKNOWN, UPDATE, UPPER, VALUE, WHEN, WHERE

Method Summary

Methods

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.
Expression	getIdentificationVariable() Returns the Expression that represents the identification variable.
java.lang.String	getIdentifier() Returns the identifier this expression represents.
Expression	getJoinAssociationPath() Returns the Expression that represents the join association path expression.
JPQLQueryBNF	getQueryBNF() Returns the BNF of this Expression.
boolean	hasAs() Determines whether the identifier AS was parsed.
boolean	hasIdentificationVariable() Determines whether the identification variable was parsed.
boolean	hasJoinAssociationPath() Determines whether the join association path expression was parsed.
boolean	hasSpaceAfterAs() Determines whether a whitespace was parsed after AS.
boolean	hasSpaceAfterJoin() Determines whether a whitespace was parsed after JOIN.
boolean	hasSpaceAfterJoinAssociation() Determines whether a whitespace was parsed after the join association path expression.
boolean	isLeftJoin() Determines whether this Join is a left join, i.e.

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

children, findQueryBNF, getChildren, getParent, getRoot, identifierRole, identifiers, identifierVersion, isAncestor, isIdentifier, isVirtual, orderedChildren, queryBNF, toActualText, toParsedText, toString

Methods inherited from class java.lang.Object

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

Method Detail

accept

public void accept(ExpressionVisitor visitor)

Visits this Expression by the given visitor.

Parameters:

visitor - The visitor 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() or Expression.getChildren() is called.

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

Parameters:

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

getIdentificationVariable

public Expression getIdentificationVariable()

Returns the Expression that represents the identification variable.

Returns:

The expression that was parsed representing the identification variable

getIdentifier

public java.lang.String getIdentifier()

Returns the identifier this expression represents.

Returns:

Either JOIN, INNER JOIN, LEFT JOIN or LEFT OUTER JOIN. Although it's possible to have an incomplete identifier if the query is not complete

getJoinAssociationPath

public Expression getJoinAssociationPath()

Returns the Expression that represents the join association path expression.

Returns:

The expression that was parsed representing the join association path expression

getQueryBNF

public JPQLQueryBNF getQueryBNF()

Returns the BNF of this Expression.

Specified by:

getQueryBNF in class AbstractExpression

Returns:

The JPQLQueryBNF, which represents the grammar of this Expression

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

hasJoinAssociationPath

public boolean hasJoinAssociationPath()

Determines whether the join association path expression was parsed.

Returns:

true if the join association path expression 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

hasSpaceAfterJoin

public boolean hasSpaceAfterJoin()

Determines whether a whitespace was parsed after JOIN.

Returns:

true if there was a whitespace after JOIN; false otherwise

hasSpaceAfterJoinAssociation

public boolean hasSpaceAfterJoinAssociation()

Determines whether a whitespace was parsed after the join association path expression.

Returns:

true if there was a whitespace after join association path expression; false otherwise

isLeftJoin

public boolean isLeftJoin()

Determines whether this Join is a left join, i.e. Expression.LEFT_JOIN or Expression.LEFT_OUTER_JOIN.

Returns:

true if this Join expression is a Expression.LEFT_JOIN or Expression.LEFT_OUTER_JOIN; false otherwise