org.mmbase.storage.search
Interface Step

All Known Subinterfaces:

RelationStep

All Known Implementing Classes:

BasicRelationStep, BasicStep

public interface Step

A step refers to a table in a search request. Several steps may refer to the same table, therefore each step has an unique alias to identify it.

This corresponds to a table name and alias in SQL SELECT-syntax.

Since:

MMBase-1.7

Version:

$Id: Step.java,v 1.2 2003/03/10 11:50:51 pierre Exp $

Author:

Rob van Maris

Method Summary

boolean	equals(java.lang.Object obj) Compares this step to the specified object.
java.lang.String	getAlias() Gets the alias associated with this step.
java.util.SortedSet	getNodes() Gets nodenumbers for nodes that must be included in this step.
java.lang.String	getTableName() Gets the name of the table referred to by this step.
int	hashCode()
java.lang.String	toString() Returns a string representation of this Step.

Method Detail

getTableName

public java.lang.String getTableName()

Gets the name of the table referred to by this step.

This corresponds to a table name in SQL SELECT-syntax.

getAlias

public java.lang.String getAlias()

Gets the alias associated with this step.

This corresponds to a table alias in SQL SELECT-syntax.

getNodes

public java.util.SortedSet getNodes()

Gets nodenumbers for nodes that must be included in this step. A null value indicates that no such constraint is applied.

This corresponds to a "number IN (....)" constraint in SQL SELECT syntax.

Note that this can also be achieved by using a FieldValueInConstraint on the "number" field.

equals

public boolean equals(java.lang.Object obj)

Compares this step to the specified object. The result is true if and only if the argument is a non-null Step, but not RelationStep, object associated with the same tablename, using the same alias and including the same nodes.

Parameters:

obj - The object to compare with.

Returns:

true if the objects are equal, false otherwise.

See Also:

RelationStep.equals(java.lang.Object)

hashCode

public int hashCode()

toString

public java.lang.String toString()

Returns a string representation of this Step. The string representation has the form "Step(tablename:<tablename>, alias:<alias>, nodes:<nodes>)" where

• <tablename> is the tablename returnedby getTableName()
• <alias> is the alias returned by getAlias()
• <nodes> is the string representation of the ordered list of nodenumbers returned by getNodes()

Returns:

A string representation of this Step.