MaxMinAggregateDefinition (Apache Derby V10.14 Internals)

java.lang.Object
- org.apache.derby.impl.sql.compile.MaxMinAggregateDefinition

All Implemented Interfaces:: AggregateDefinition

class MaxMinAggregateDefinition
extends java.lang.Object
implements AggregateDefinition

Defintion for the MAX()/MIN() aggregates.

Field Summary

Fields
Modifier and Type Field Description

private boolean isMax

Constructor Summary

Constructors
Constructor Description

MaxMinAggregateDefinition()
Niladic constructor.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`DataTypeDescriptor`	`getAggregator(DataTypeDescriptor inputType, java.lang.StringBuffer aggregatorClass)`	Determines the result datatype.
`(package private) boolean`	`isMax()`	Return if the aggregator class is for min/max.
`(package private) void`	`setMaxOrMin(boolean isMax)`	This is set by the parser.

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

- Field Detail
  - isMax
```
private boolean isMax
```
- Constructor Detail
  - MaxMinAggregateDefinition
```
public MaxMinAggregateDefinition()
```
    Niladic constructor. Does nothing. For ease Of use, only.
- Method Detail
  - getAggregator
```
public final DataTypeDescriptor getAggregator(DataTypeDescriptor inputType,
                                              java.lang.StringBuffer aggregatorClass)
```
    Determines the result datatype. Accept NumberDataValues only.
    Note: In the future you should be able to do a sum user data types. One option would be to run sum on anything that implements divide().
    
    Specified by:
    
    getAggregator in interface AggregateDefinition
    
    Parameters:
    
    inputType - the input type, either a user type or a java.lang object
    
    aggregatorClass - output parameter, filled in with the class name that implements com.ibm.db2j.aggregates.Aggregator
    
    Returns:
    
    the output Class (null if cannot operate on value expression of this type.
    
    See Also:
    
    TypeDescriptor
  - setMaxOrMin
```
final void setMaxOrMin(boolean isMax)
```
    This is set by the parser.
  - isMax
```
final boolean isMax()
```
    Return if the aggregator class is for min/max.
    
    Returns:
    
    boolean true/false