AggregateExpressionBNF (EclipseLink 2.7.15, API Reference)

java.lang.Object
- org.eclipse.persistence.jpa.jpql.parser.JPQLQueryBNF
- - org.eclipse.persistence.jpa.jpql.parser.AggregateExpressionBNF

```
public final class AggregateExpressionBNF
extends JPQLQueryBNF
```
The query BNF for an aggregate expression.
JPA 1.0, 2.0:
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)
JPA 2.1:
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) | function_invocation

Version:

2.4

Author:

Pascal Filion

Since:

2.3

Field Summary

Fields
Modifier and Type Field Description

static java.lang.String ID
The unique identifier of this BNF rule.

Constructor Summary

Constructors
Constructor Description

AggregateExpressionBNF()
Creates a new AggregateExpressionBNF.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`protected void`	`initialize()`	Initializes this BNF by registering child `JPQLQueryBNFs` and `ExpressionFactories`.

Methods inherited from class org.eclipse.persistence.jpa.jpql.parser.JPQLQueryBNF
children, getExpressionFactory, getExpressionFactoryIds, getExpressionRegistry, getFallbackBNFId, getFallbackExpressionFactoryId, getId, getIdentifiers, handleAggregate, handleCollection, handlesNestedArray, handleSubExpression, hasChild, hasIdentifier, isCompound, nonCompoundChildren, registerChild, registerExpressionFactory, setCompound, setFallbackBNFId, setFallbackExpressionFactoryId, setHandleAggregate, setHandleCollection, setHandleNestedArray, setHandleSubExpression, toString, toString

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Field Detail
  - ID
```
public static final java.lang.String ID
```
    The unique identifier of this BNF rule.
    
    See Also:
    
    Constant Field Values
- Constructor Detail
  - AggregateExpressionBNF
```
public AggregateExpressionBNF()
```
    Creates a new AggregateExpressionBNF.
- Method Detail
  - initialize
```
protected void initialize()
```
    Initializes this BNF by registering child JPQLQueryBNFs and ExpressionFactories.
    
    Overrides:
    
    initialize in class JPQLQueryBNF