org.eclipse.persistence.jpa.jpql.parser
Class AggregateFunction

java.lang.Object
  org.eclipse.persistence.jpa.jpql.parser.AbstractExpression
      org.eclipse.persistence.jpa.jpql.parser.AbstractEncapsulatedExpression
          org.eclipse.persistence.jpa.jpql.parser.AbstractSingleEncapsulatedExpression
              org.eclipse.persistence.jpa.jpql.parser.AggregateFunction

All Implemented Interfaces:

Expression

Direct Known Subclasses:

AvgFunction, CountFunction, MaxFunction, MinFunction, SumFunction

public abstract class AggregateFunction
extends AbstractSingleEncapsulatedExpression

In the SELECT clause the result of a query may be the result of an aggregate function applied to a path expression. The following aggregate functions can be used in the SELECT clause of a query: AVG, COUNT, MAX, MIN, SUM.

A single_valued_association_field is designated by the name of an association-field in a one-to-one or many-to-one relationship. The type of a single_valued_association_field and thus a single_valued_association_path_expression is the abstract schema type of the related entity.

The argument to an aggregate function may be preceded by the keyword DISTINCT to specify that duplicate values are to be eliminated before the aggregate function is applied. Null values are eliminated before the aggregate function is applied, regardless of whether the keyword DISTINCT is specified.

BNF: aggregate_expression ::= { AVG | MAX | MIN | SUM } ([DISTINCT] state_field_path_expression) | COUNT ([DISTINCT] identification_variable | state_field_path_expression | single_valued_object_path_expression)

Version:

2.4

See Also:

AvgFunction, CountFunction, MaxFunction, MinFunction, SumFunction

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, ASC, AVG, BETWEEN, BIT_LENGTH, BOTH, CASE, CAST, CHAR_LENGTH, CHARACTER_LENGTH, CLASS, COALESCE, COLUMN, CONCAT, 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, 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, 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_FIRST, NULLS_LAST, OBJECT, OF, ON, OPERATOR, OR, ORDER_BY, OUTER, PLUS, POSITION, POSITIONAL_PARAMETER, QUOTE, REGEXP, SELECT, SET, SIZE, SOME, SQL, SQRT, SUBSTRING, SUM, TABLE, THEN, TRAILING, TREAT, TRIM, TRUE, TYPE, UNION, UNKNOWN, UPDATE, UPPER, VALUE, WHEN, WHERE

Constructor Summary

protected

AggregateFunction(AbstractExpression parent) Creates a new AggregateFunction.

Method Summary

protected void	addOrderedEncapsulatedExpressionTo(java.util.List<Expression> children) Adds the Expressions representing the encapsulated Expression.
protected AbstractExpression	buildEncapsulatedExpression(WordParser wordParser, java.lang.String word) Creates the AbstractExpression to represent the given word.
java.lang.String	encapsulatedExpressionBNF() Returns the BNF used to parse the encapsulated expression.
java.lang.String	getActualDistinctIdentifier() Returns the actual DISTINCT identifier 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.
boolean	hasDistinct() Determines whether the DISTINCT identifier was specified in the query.
boolean	hasSpaceAfterDistinct() Determines whether a whitespace was parsed after DISTINCT.
protected void	parseEncapsulatedExpression(WordParser wordParser, int whitespaceCount, boolean tolerant) Parses the encapsulated expression by starting at the current position, which is part of the given WordParser.
protected void	toParsedTextEncapsulatedExpression(java.lang.StringBuilder writer, boolean actual) Generates a string representation of the encapsulated Expression.

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

acceptChildren, addChildrenTo, findQueryBNF, getExpression, hasEncapsulatedExpression, hasExpression, removeEncapsulatedExpression, setExpression

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

addOrderedChildrenTo, areLogicalIdentifiersSupported, getActualIdentifier, getIdentifier, hasLeftParenthesis, hasRightParenthesis, hasSpaceAfterIdentifier, isParsingComplete, parse, parseIdentifier, shouldParseRightParenthesis, toParsedText

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

Methods inherited from interface org.eclipse.persistence.jpa.jpql.parser.Expression

accept

Constructor Detail

AggregateFunction

protected AggregateFunction(AbstractExpression parent)

Creates a new AggregateFunction.

Parameters:

parent - The parent of this expression

Method Detail

getActualDistinctIdentifier

public java.lang.String getActualDistinctIdentifier()

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

Returns:

The DISTINCT identifier that was actually parsed, or an empty string if it was not parsed

addOrderedEncapsulatedExpressionTo

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

Adds the Expressions representing the encapsulated Expression.

Overrides:

addOrderedEncapsulatedExpressionTo in class AbstractSingleEncapsulatedExpression

Parameters:

children - The list used to store the string representation of the encapsulated Expression

buildEncapsulatedExpression

protected AbstractExpression buildEncapsulatedExpression(WordParser wordParser,
                                                         java.lang.String word)

Creates the AbstractExpression to represent the given word.

Parameters:

word - The word that was parsed

Returns:

The encapsulated AbstractExpression

encapsulatedExpressionBNF

public java.lang.String encapsulatedExpressionBNF()

Returns the BNF used to parse the encapsulated expression.

Specified by:

encapsulatedExpressionBNF in class AbstractSingleEncapsulatedExpression

Returns:

The BNF used to parse the encapsulated expression

getQueryBNF

public JPQLQueryBNF getQueryBNF()

Returns the BNF of this Expression.

Returns:

The JPQLQueryBNF, which represents the grammar of this Expression

hasDistinct

public final boolean hasDistinct()

Determines whether the DISTINCT identifier was specified in the query.

Returns:

true if the query has DISTINCT; false otherwise

hasSpaceAfterDistinct

public final boolean hasSpaceAfterDistinct()

Determines whether a whitespace was parsed after DISTINCT.

Returns:

true if there was a whitespace after DISTINCT; false otherwise

parseEncapsulatedExpression

protected final void parseEncapsulatedExpression(WordParser wordParser,
                                                 int whitespaceCount,
                                                 boolean tolerant)

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

Overrides:

parseEncapsulatedExpression in class AbstractSingleEncapsulatedExpression

Parameters:

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

whitespaceCount - The number of whitespace characters that were parsed after '('

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

toParsedTextEncapsulatedExpression

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

Generates a string representation of the encapsulated Expression.

Overrides:

toParsedTextEncapsulatedExpression in class AbstractSingleEncapsulatedExpression

Parameters:

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

actual - Determines whether to include any characters that are considered virtual, i.e. that was parsed when the query is incomplete and is needed for functionality like content assist