org.mmbase.storage.search
Interface AggregatedField

All Superinterfaces:

StepField

All Known Implementing Classes:

BasicAggregatedField

public interface AggregatedField

extends StepField

A field in an aggregated query.

Each field in a aggregated query has an aggregation type, which is one of the values listed below. This corresponds to an aggregated field in SQL SELECT-syntax.

Since:

MMBase-1.7

Version:

$Id: AggregatedField.java,v 1.3 2003/03/10 11:50:42 pierre Exp $

Author:

Rob van Maris

Field Summary

static int	AGGREGATION_TYPE_COUNT Aggregation type, resulting in count of non-null values in this field.
static int	AGGREGATION_TYPE_COUNT_DISTINCT Aggregation type, resulting in count of distinct non-null values in this field.
static int	AGGREGATION_TYPE_GROUP_BY Aggregation type, resulting in grouping the results on non-null values of this field.
static int	AGGREGATION_TYPE_MAX Aggregation type, resulting in maximum value in this field.
static int	AGGREGATION_TYPE_MIN Aggregation type, resulting in minimum value in this field.

Method Summary

boolean	equals(java.lang.Object obj) Compares this aggregated field to the specified object.
int	getAggregationType() Gets the aggregation type.
java.lang.String	toString() Returns a string representation of this AggregatedField.

Methods inherited from interface org.mmbase.storage.search.StepField

getAlias, getFieldName, getStep, getType, hashCode

Field Detail

AGGREGATION_TYPE_GROUP_BY

public static final int AGGREGATION_TYPE_GROUP_BY

Aggregation type, resulting in grouping the results on non-null values of this field.

See Also:

Constant Field Values

AGGREGATION_TYPE_COUNT

public static final int AGGREGATION_TYPE_COUNT

Aggregation type, resulting in count of non-null values in this field.

See Also:

Constant Field Values

AGGREGATION_TYPE_COUNT_DISTINCT

public static final int AGGREGATION_TYPE_COUNT_DISTINCT

Aggregation type, resulting in count of distinct non-null values in this field.

See Also:

Constant Field Values

AGGREGATION_TYPE_MIN

public static final int AGGREGATION_TYPE_MIN

Aggregation type, resulting in minimum value in this field.

See Also:

Constant Field Values

AGGREGATION_TYPE_MAX

public static final int AGGREGATION_TYPE_MAX

Aggregation type, resulting in maximum value in this field.

See Also:

Constant Field Values

Method Detail

getAggregationType

public int getAggregationType()

Gets the aggregation type.

equals

public boolean equals(java.lang.Object obj)

Compares this aggregated field to the specified object. The result is true if and only if the argument is a non-null AggregatedField object associated with the same field, using the same alias, and having the same aggregation type.

Specified by:

equals in interface StepField

Parameters:

obj - The object to compare with.

Returns:

true if the objects are equal, false otherwise.

toString

public java.lang.String toString()

Returns a string representation of this AggregatedField. The string representation has the form "AggregatedField(step:<step>, fieldname:<fieldname>, alias:<alias>, aggregationtype:<aggregationtype>)" where

• <step> is the step alias returned by getStep().getAlias() or, when the step alias is null, the step tablename returned by getStep().getTableName().
• <fieldname> is the fieldname returned by getFieldName()
• <alias> is the alias returned by getAlias()
• <aggregationtype> is the alias returned by getAggregationType()

Specified by:

toString in interface StepField

Returns:

A string representation of this AggregatedField.