EclipseLink 2.4.2, build 'v20130514-5956486' API Reference

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

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

EclipseLink 2.4.2, build 'v20130514-5956486' API Reference