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

Class UnionClause

java.lang.Object

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

org.eclipse.persistence.jpa.jpql.parser.UnionClause

All Implemented Interfaces:

Expression

public final class UnionClause
extends AbstractExpression

The UNION clause allows the results of two queries to be combined.

BNF: union_clause ::= { UNION | INTERSECT | EXCEPT } [ALL] subquery

Version:

2.5

Author:

James Sutherland

Since:

2.4

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
UnionClause(AbstractExpression parent, java.lang.String identifier)	Creates a new UnionClause.

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	getActualAll()	Returns the actual ALL found in the string representation of the JPQL query, which has the actual case that was used.
java.lang.String	getActualIdentifier()	Returns the actual identifier found in the string representation of the JPQL query, which has the actual case that was used.
java.lang.String	getIdentifier()	Returns the union identifier.
Expression	getQuery()	Returns the Expression representing the unioned query.
JPQLQueryBNF	getQueryBNF()	Returns the BNF of this Expression.
boolean	hasAll()	Determines whether ALL was parsed.
boolean	hasQuery()	Determines whether the query was parsed.
boolean	hasSpaceAfterAll()	Determines whether a whitespace was parsed after ALL.
boolean	hasSpaceAfterIdentifier()	Determines whether a whitespace was parsed after the identifier.
boolean	isExcept()	Determines whether this UnionClause uses the EXCEPT identifier.
boolean	isIntersect()	Determines whether this UnionClause uses the INTERSECT identifier.
protected boolean	isParsingComplete(WordParser wordParser, java.lang.String word, Expression expression)	Determines whether the parsing is complete based on what is left in the given text.
boolean	isUnion()	Determines whether this UnionClause uses the UNION identifier.
protected void	parse(WordParser wordParser, boolean tolerant)	Parses the query by starting at the current position, which is part of the given WordParser.
protected java.lang.String	parseIdentifier()	Parses the JPQL identifier identifier the type of union.
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, 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

UnionClause

public UnionClause(AbstractExpression parent,
                   java.lang.String identifier)

Creates a new UnionClause.

Parameters:

parent - The parent of this expression

identifier - Either UNION, INTERSECT or EXCEPT

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

getActualAll

public java.lang.String getActualAll()

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

Returns:

The ALL identifier that was actually parsed

getActualIdentifier

public java.lang.String getActualIdentifier()

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

Returns:

The identifier that was actually parsed

getIdentifier

public java.lang.String getIdentifier()

Returns the union identifier.

Returns:

Either "UNION", "INTERSECT", "EXCEPT"

getQuery

public Expression getQuery()

Returns the Expression representing the unioned query.

Returns:

The Expression representing the subquery

getQueryBNF

public JPQLQueryBNF getQueryBNF()

Returns the BNF of this Expression.

Returns:

The JPQLQueryBNF, which represents the grammar of this Expression

hasAll

public boolean hasAll()

Determines whether ALL was parsed.

Returns:

true if ALL was parsed; false otherwise

hasQuery

public boolean hasQuery()

Determines whether the query was parsed.

Returns:

true the query was parsed; false otherwise

hasSpaceAfterAll

public boolean hasSpaceAfterAll()

Determines whether a whitespace was parsed after ALL.

Returns:

true if a whitespace was parsed after ALL; false otherwise

hasSpaceAfterIdentifier

public boolean hasSpaceAfterIdentifier()

Determines whether a whitespace was parsed after the identifier.

Returns:

true if a whitespace was parsed after the identifier; false otherwise

isExcept

public boolean isExcept()

Determines whether this UnionClause uses the EXCEPT identifier.

Returns:

true if the identifier is EXCEPT; false otherwise

isIntersect

public boolean isIntersect()

Determines whether this UnionClause uses the INTERSECT identifier.

Returns:

true if the identifier is INTERSECT; false otherwise

isParsingComplete

protected boolean isParsingComplete(WordParser wordParser,
                                    java.lang.String word,
                                    Expression expression)

Determines whether the parsing is complete based on what is left in the given text. The text is never empty.

Overrides:

isParsingComplete in class AbstractExpression

Parameters:

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

word - The word that was retrieved from the given text, which is the first word in the text

expression - The Expression that has already been parsed

Returns:

true if the text no longer can't be parsed by the current expression; false if more can be parsed

isUnion

public boolean isUnion()

Determines whether this UnionClause uses the UNION identifier.

Returns:

true if the identifier is UNION; 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

parseIdentifier

protected java.lang.String parseIdentifier()

Parses the JPQL identifier identifier the type of union.

Returns:

Either UNION, INTERSECT or EXCEPT

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