Package org.eclipse.persistence.jpa.jpql.parser

Class ResultVariable

java.lang.Object

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

org.eclipse.persistence.jpa.jpql.parser.ResultVariable

All Implemented Interfaces:

Expression

public final class ResultVariable
extends AbstractExpression

A result variable may be used to name a select item in the query result.

BNF: select_item ::= select_expression [[AS] result_variable]

Version:

2.5

Author:

Pascal Filion

Since:

2.3

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	Description
ResultVariable(AbstractExpression parent, AbstractExpression selectExpression)	Creates a new ResultVariable.

Method Summary

Modifier and Type	Method	Description
void	accept(ExpressionVisitor visitor)	Visits this Expression by the given visitor.
void	acceptChildren(ExpressionVisitor visitor)	Visits the children of this Expression.
protected void	addChildrenTo(java.util.Collection<Expression> children)	Adds the children of this AbstractExpression to the given collection.
protected void	addOrderedChildrenTo(java.util.List<Expression> children)	Adds the children of this AbstractExpression to the given list.
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.
JPQLQueryBNF	getQueryBNF()	Returns the BNF of this Expression.
Expression	getResultVariable()	Returns the Expression representing the result variable.
Expression	getSelectExpression()	Returns the Expression representing the select expression.
boolean	hasAs()	Determines whether the identifier AS was parsed or not.
boolean	hasResultVariable()	Determines whether the result variable was parsed.
boolean	hasSelectExpression()	Determines whether a select expression was defined for this result variable.
boolean	hasSpaceAfterAs()	Determines whether a whitespace was parsed after the identifier AS.
protected void	parse(WordParser wordParser, boolean tolerant)	Parses the query by starting at the current position, which is part of the given WordParser.
protected void	toParsedText(java.lang.StringBuilder writer, boolean actual)	Generates a string representation of this Expression, including its children, if it has any.

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

acceptUnknownVisitor, acceptUnknownVisitor, buildExpressionFromFallingBack, buildNullExpression, buildStringExpression, buildStringExpression, buildUnknownExpression, calculatePosition, children, findFallBackExpressionFactory, getExpressionFactory, getExpressionRegistry, getGrammar, getIdentifierVersion, getJPAVersion, getLength, getOffset, getParent, getQueryBNF, getRoot, getText, handleAggregate, handleCollection, isAncestor, isIdentifier, isNull, isParsingComplete, isTolerant, isUnknown, isVirtual, orderedChildren, parse, parseUsingExpressionFactory, populatePosition, rebuildActualText, rebuildParsedText, setParent, setText, shouldParseWithFactoryFirst, shouldSkipLiteral, toActualText, toParsedText, toString

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

ResultVariable

public ResultVariable(AbstractExpression parent,
                      AbstractExpression selectExpression)

Creates a new ResultVariable.

Parameters:

parent - The parent of this expression

selectExpression - The expression that represents the select expression, which will have a variable assigned to it

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.

addChildrenTo

protected void addChildrenTo(java.util.Collection<Expression> children)

Adds the children of this AbstractExpression to the given collection.

Overrides:

addChildrenTo in class AbstractExpression

Parameters:

children - The collection used to store the children

addOrderedChildrenTo

protected void addOrderedChildrenTo(java.util.List<Expression> children)

Adds the children of this AbstractExpression to the given list.

Overrides:

addOrderedChildrenTo in class AbstractExpression

Parameters:

children - The list used to store the string representation of this AbstractExpression

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

getQueryBNF

public JPQLQueryBNF getQueryBNF()

Returns the BNF of this Expression.

Returns:

The JPQLQueryBNF, which represents the grammar of this Expression

getResultVariable

public Expression getResultVariable()

Returns the Expression representing the result variable.

Returns:

The expression for the result variable

getSelectExpression

public Expression getSelectExpression()

Returns the Expression representing the select expression.

Returns:

The expression for the select expression

hasAs

public boolean hasAs()

Determines whether the identifier AS was parsed or not.

Returns:

true if the identifier AS was parsed; false otherwise

hasResultVariable

public boolean hasResultVariable()

Determines whether the result variable was parsed.

Returns:

true if the result variable was parsed; false otherwise

hasSelectExpression

public boolean hasSelectExpression()

Determines whether a select expression was defined for this result variable.

Returns:

true if the select expression was parsed; false if the result variable was parsed without one

hasSpaceAfterAs

public boolean hasSpaceAfterAs()

Determines whether a whitespace was parsed after the identifier AS.

Returns:

true if there was a whitespace after AS; false otherwise

parse

protected void parse(WordParser wordParser,
                     boolean tolerant)

Parses the query by starting at the current position, which is part of the given WordParser.

Specified by:

parse in class AbstractExpression

Parameters:

wordParser - The text to parse based on the current position of the cursor

tolerant - Determines whether the parsing system should be tolerant, meaning if it should try to parse invalid or incomplete queries

toParsedText

protected void toParsedText(java.lang.StringBuilder writer,
                            boolean actual)

Generates a string representation of this Expression, including its children, if it has any.

Specified by:

toParsedText in class AbstractExpression

Parameters:

writer - The buffer used to append this Expression's string representation

actual - Determines whether the string representation should represent what was parsed, i.e. include any "virtual" whitespace (such as ending whitespace) and the actual case of the JPQL identifiers