org.eclipse.persistence.jpa.jpql.parser

Class GroupByClause

java.lang.Object

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

org.eclipse.persistence.jpa.jpql.parser.GroupByClause

All Implemented Interfaces:

Expression

public final class GroupByClause
extends AbstractExpression

The GROUP BY construct enables the aggregation of values according to the properties of an entity class.

BNF: groupby_clause ::= GROUP BY groupby_item {, groupby_item}*

Since:

2.3

Version:

2.5.1

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
GroupByClause(AbstractExpression parent) Creates a new GroupByClause.

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.
CollectionExpression	buildCollectionExpression() Creates a new CollectionExpression that will wrap the single group by item.
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	getActualIdentifier() Returns the actual GROUP BY found in the string representation of the JPQL query, which has the actual case that was used.
Expression	getGroupByItems() Returns the Expression that represents the list of group by items if any was parsed.
JPQLQueryBNF	getQueryBNF() Returns the BNF of this Expression.
boolean	hasGroupByItems() Determines whether the list of items was parsed.
boolean	hasSpaceAfterGroupBy() Determines whether a whitespace was found after GROUP BY.

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

GroupByClause

public GroupByClause(AbstractExpression parent)

Creates a new GroupByClause.

Parameters:

parent - The parent of this expression

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.

buildCollectionExpression

public CollectionExpression buildCollectionExpression()

Creates a new CollectionExpression that will wrap the single group by item.

Returns:

The single group by item represented by a temporary collection

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

getActualIdentifier

public java.lang.String getActualIdentifier()

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

Returns:

The GROUP BY identifier that was actually parsed

getGroupByItems

public Expression getGroupByItems()

Returns the Expression that represents the list of group by items if any was parsed.

Returns:

The expression that was parsed representing the list of items

getQueryBNF

public JPQLQueryBNF getQueryBNF()

Returns the BNF of this Expression.

Returns:

The JPQLQueryBNF, which represents the grammar of this Expression

hasGroupByItems

public boolean hasGroupByItems()

Determines whether the list of items was parsed.

Returns:

true if at least one item was parsed; false otherwise

hasSpaceAfterGroupBy

public boolean hasSpaceAfterGroupBy()

Determines whether a whitespace was found after GROUP BY.

Returns:

true if there was a whitespace after GROUP BY; false otherwise