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

Class JoinFetch

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.JoinFetch

All Implemented Interfaces:

Expression

public final class JoinFetch
extends AbstractExpression

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

BNF: fetch_join ::= join_spec FETCH join_association_path_expression

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.
java.lang.String	getIdentifier() Returns the identifier this expression represents.
Expression	getJoinAssociationPath() Returns the Expression that represents the join association path expression if it was parsed.
JPQLQueryBNF	getQueryBNF() Returns the BNF of this Expression.
boolean	hasJoinAssociationPath() Determines whether the join association path expression was parsed.
boolean	hasSpaceAfterFetch() Determines whether a whitespace was found after FETCH.
boolean	isLeftJoinFetch() Determines whether this JoinFetch is a left join fetch, 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.

getIdentifier

public java.lang.String getIdentifier()

Returns the identifier this expression represents.

Returns:

Either INNER JOIN FETCH, JOIN FETCH, LEFT JOIN_FETCH or LEFT OUTER JOIN_FETCH. 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 if it was parsed.

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

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

hasSpaceAfterFetch

public boolean hasSpaceAfterFetch()

Determines whether a whitespace was found after FETCH.

Returns:

true if there was a whitespace after FETCH; false otherwise

isLeftJoinFetch

public boolean isLeftJoinFetch()

Determines whether this JoinFetch is a left join fetch, i.e. Expression.LEFT_JOIN_FETCH or Expression.LEFT_OUTER_JOIN_FETCH.

Returns:

true if this JoinFetch expression is a Expression.LEFT_JOIN_FETCH or Expression.LEFT_OUTER_JOIN_FETCH; false otherwise