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java.lang.Objectorg.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
public abstract class AggregateFunction
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.
aggregate_expression ::= { AVG | MAX | MIN | SUM } ([DISTINCT] state_field_path_expression) |
COUNT ([DISTINCT] identification_variable |
state_field_path_expression |
single_valued_object_path_expression)
AvgFunction
,
CountFunction
,
MaxFunction
,
MinFunction
,
SumFunction
Field Summary |
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Fields inherited from class org.eclipse.persistence.jpa.jpql.parser.AbstractExpression |
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COMMA, DOT, DOUBLE_QUOTE, LEFT_CURLY_BRACKET, LEFT_PARENTHESIS, NOT_DEFINED, RIGHT_CURLY_BRACKET, RIGHT_PARENTHESIS, SINGLE_QUOTE, SPACE, UNDERSCORE |
Constructor Summary | |
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protected |
AggregateFunction(AbstractExpression parent)
Creates a new AggregateFunction . |
Method Summary | |
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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 |
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acceptChildren, addChildrenTo, findQueryBNF, getExpression, hasEncapsulatedExpression, hasExpression, removeEncapsulatedExpression, setExpression |
Methods inherited from class org.eclipse.persistence.jpa.jpql.parser.AbstractEncapsulatedExpression |
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addOrderedChildrenTo, areLogicalIdentifiersSupported, getActualIdentifier, getIdentifier, hasLeftParenthesis, hasRightParenthesis, hasSpaceAfterIdentifier, isParsingComplete, parse, parseIdentifier, shouldParseRightParenthesis, toParsedText |
Methods inherited from class java.lang.Object |
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clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait |
Methods inherited from interface org.eclipse.persistence.jpa.jpql.parser.Expression |
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accept |
Constructor Detail |
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protected AggregateFunction(AbstractExpression parent)
AggregateFunction
.
parent
- The parent of this expressionMethod Detail |
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public java.lang.String getActualDistinctIdentifier()
protected void addOrderedEncapsulatedExpressionTo(java.util.List<Expression> children)
Expressions
representing the encapsulated Expression
.
addOrderedEncapsulatedExpressionTo
in class AbstractSingleEncapsulatedExpression
children
- The list used to store the string representation of the encapsulated Expression
protected AbstractExpression buildEncapsulatedExpression(WordParser wordParser, java.lang.String word)
AbstractExpression
to represent the given word.
word
- The word that was parsed
AbstractExpression
public java.lang.String encapsulatedExpressionBNF()
encapsulatedExpressionBNF
in class AbstractSingleEncapsulatedExpression
public JPQLQueryBNF getQueryBNF()
Expression
.
JPQLQueryBNF
, which represents the grammar of this Expression
public final boolean hasDistinct()
true
if the query has DISTINCT; false
otherwisepublic final boolean hasSpaceAfterDistinct()
true
if there was a whitespace after DISTINCT; false
otherwiseprotected final void parseEncapsulatedExpression(WordParser wordParser, int whitespaceCount, boolean tolerant)
WordParser
.
parseEncapsulatedExpression
in class AbstractSingleEncapsulatedExpression
wordParser
- The text to parse based on the current position of the cursorwhitespaceCount
- 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 queriesprotected void toParsedTextEncapsulatedExpression(java.lang.StringBuilder writer, boolean actual)
Expression
.
toParsedTextEncapsulatedExpression
in class AbstractSingleEncapsulatedExpression
writer
- The buffer used to append the encapsulated Expression
's string
representationactual
- 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
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EclipseLink 2.4.2, build 'v20130514-5956486' API Reference | ||||||||
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