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

java.lang.Object
  extended by org.apache.openjpa.jdbc.meta.strats.AbstractStrategy
      extended by org.apache.openjpa.jdbc.meta.strats.AbstractDiscriminatorStrategy
          extended by org.apache.openjpa.jdbc.meta.strats.SubclassJoinDiscriminatorStrategy
All Implemented Interfaces:
Serializable, 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
See Also:
Serialized Form

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.
 boolean hasClassConditions(ClassMapping base, boolean subclasses)
          Whether any class conditions are necessary.
 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

hasClassConditions

public boolean hasClassConditions(ClassMapping base,
                                  boolean subclasses)
Description copied from interface: DiscriminatorStrategy
Whether any class conditions are necessary.

Specified by:
hasClassConditions in interface DiscriminatorStrategy
Overrides:
hasClassConditions in class AbstractDiscriminatorStrategy
See Also:
DiscriminatorStrategy.getClassConditions(org.apache.openjpa.jdbc.sql.Select, org.apache.openjpa.jdbc.sql.Joins, org.apache.openjpa.jdbc.meta.ClassMapping, boolean)

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. The select and joins instances are supplied in order to get column aliases.

Specified by:
getClassConditions in interface DiscriminatorStrategy
Overrides:
getClassConditions in class AbstractDiscriminatorStrategy


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