org.apache.openjpa.jdbc.meta.strats
Class SubclassJoinDiscriminatorStrategy

java.lang.Object
  org.apache.openjpa.jdbc.meta.strats.AbstractStrategy
      org.apache.openjpa.jdbc.meta.strats.AbstractDiscriminatorStrategy
          org.apache.openjpa.jdbc.meta.strats.SubclassJoinDiscriminatorStrategy

All Implemented Interfaces:

DiscriminatorStrategy, Strategy

public class SubclassJoinDiscriminatorStrategy
extends AbstractDiscriminatorStrategy

Discriminator strategy that outer joins to all possible subclass tables to determine the class of an instance. This indicator type should only be used with vertical inheritance hierarchies.

Author:

Abe White

Field Summary

static String

ALIAS

Fields inherited from class org.apache.openjpa.jdbc.meta.strats.AbstractDiscriminatorStrategy

disc, isFinal

Constructor Summary

SubclassJoinDiscriminatorStrategy()

Method Summary

String	getAlias() Return the alias of this strategy.
Class	getClass(JDBCStore store, ClassMapping base, Result res) Return the class for the current result row.
SQLBuffer	getClassConditions(Select sel, Joins joins, ClassMapping base, boolean subclasses) Return SQL to limit the classes selected as much as possible to the given base class, and optionally its subclasses.
void	map(boolean adapt) Map the owning mapping using this strategy.
boolean	select(Select sel, ClassMapping mapping) Select the data for this Discriminator.

Methods inherited from class org.apache.openjpa.jdbc.meta.strats.AbstractDiscriminatorStrategy

loadSubclasses, setDiscriminator

Methods inherited from class org.apache.openjpa.jdbc.meta.strats.AbstractStrategy

customDelete, customInsert, customUpdate, delete, initialize, insert, isCustomDelete, isCustomInsert, isCustomUpdate, update

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.apache.openjpa.jdbc.meta.Strategy

customDelete, customInsert, customUpdate, delete, initialize, insert, isCustomDelete, isCustomInsert, isCustomUpdate, update

Field Detail

ALIAS

public static final String ALIAS

See Also:

Constant Field Values

Constructor Detail

SubclassJoinDiscriminatorStrategy

public SubclassJoinDiscriminatorStrategy()

Method Detail

getAlias

public String getAlias()

Description copied from interface: Strategy

Return the alias of this strategy. For custom strategies, return the full class name.

Specified by:

getAlias in interface Strategy

Overrides:

getAlias in class AbstractStrategy

map

public void map(boolean adapt)

Description copied from interface: Strategy

Map the owning mapping using this strategy.

Specified by:

map in interface Strategy

Overrides:

map in class AbstractStrategy

Parameters:

adapt - if true, use the owning mapping's raw mapping info to set its ORM data; if false, ORM data will already be set

select

public boolean select(Select sel,
                      ClassMapping mapping)

Description copied from interface: DiscriminatorStrategy

Select the data for this Discriminator.

Specified by:

select in interface DiscriminatorStrategy

Overrides:

select in class AbstractDiscriminatorStrategy

mapping - the known base class being selected; this may not be the base class in the inheritance hierarchy

Returns:

true if anything was selected; false otherwise

getClass

public Class getClass(JDBCStore store,
                      ClassMapping base,
                      Result res)
               throws SQLException,
                      ClassNotFoundException

Description copied from interface: DiscriminatorStrategy

Return the class for the current result row.

Specified by:

getClass in interface DiscriminatorStrategy

Overrides:

getClass in class AbstractDiscriminatorStrategy

Throws:

SQLException

ClassNotFoundException

getClassConditions

public SQLBuffer getClassConditions(Select sel,
                                    Joins joins,
                                    ClassMapping base,
                                    boolean subclasses)

Description copied from interface: DiscriminatorStrategy

Return SQL to limit the classes selected as much as possible to the given base class, and optionally its subclasses. Return null if no conditions needed. The select and joins instances are supplied in order to get column aliases.

Specified by:

getClassConditions in interface DiscriminatorStrategy

Overrides:

getClassConditions in class AbstractDiscriminatorStrategy