org.apache.openjpa.jdbc.meta
Interface ClassStrategy

All Superinterfaces:

Serializable, Strategy

All Known Implementing Classes:

AbstractClassStrategy, ClassMapping, EmbeddedClassStrategy, FlatClassStrategy, FullClassStrategy, NoneClassStrategy, ObjectIdClassStrategy, VerticalClassStrategy

public interface ClassStrategy
extends Strategy

Mapping from a class to a relational schema.

Since:

0.4.0

Author:

Abe White

Method Summary

ResultObjectProvider	customLoad(JDBCStore store, boolean subclasses, JDBCFetchConfiguration fetch, long startIdx, long endIdx) Implement this method to customize obtaining a result containing all instances of this class.
boolean	customLoad(OpenJPAStateManager sm, JDBCStore store, JDBCFetchConfiguration fetch, Result result) Implement this method to customize loading from a Result into an instance.
boolean	customLoad(OpenJPAStateManager sm, JDBCStore store, PCState state, JDBCFetchConfiguration fetch) Implement this method to load the state of a given object, without a previous Result.
boolean	isPrimaryKeyObjectId(boolean hasAll) Return true if the this class' primary key columns correspond to the base class' primary key columns used to construct oid values.
Joins	joinSuperclass(Joins joins, boolean toThis) Join the mapping and its superclass.
void	setClassMapping(ClassMapping owner) Set the class mapping using this strategy.
boolean	supportsEagerSelect(Select sel, OpenJPAStateManager sm, JDBCStore store, ClassMapping base, JDBCFetchConfiguration fetch) Return true if this strategy can perform the given select from the given base mapping.

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

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

Method Detail

setClassMapping

void setClassMapping(ClassMapping owner)

Set the class mapping using this strategy. This will be called before use.

isPrimaryKeyObjectId

boolean isPrimaryKeyObjectId(boolean hasAll)

Return true if the this class' primary key columns correspond to the base class' primary key columns used to construct oid values. Base classes always return true. Classes that join to the base class table, though, may not always join using the same columns the base class uses for oid values, or may not use all the columns. When performing a select, we will join down to the most-derived class that is identified by oid values. We cannot use non-primary key field values for joining during selects, because the field values to join on might be the ones we're trying to select! Similarly, we can only reconstruct oid values for selected objects using classes whose primary keys store oid values.

Parameters:

hasAll - if true, there must be a primary key column for every base class primary key column; if false the primary key must only match a subset of the base class primary key columns

joinSuperclass

Joins joinSuperclass(Joins joins,
                     boolean toThis)

Join the mapping and its superclass.

Parameters:

toThis - if false, inner join to the superclass table; if true, outer join from the superclass table to this table

supportsEagerSelect

boolean supportsEagerSelect(Select sel,
                            OpenJPAStateManager sm,
                            JDBCStore store,
                            ClassMapping base,
                            JDBCFetchConfiguration fetch)

Return true if this strategy can perform the given select from the given base mapping. The given state manager may be null if selecting multiple instances.

customLoad

ResultObjectProvider customLoad(JDBCStore store,
                                boolean subclasses,
                                JDBCFetchConfiguration fetch,
                                long startIdx,
                                long endIdx)
                                throws SQLException

Implement this method to customize obtaining a result containing all instances of this class. Return null for standard loading.

Throws:

SQLException

customLoad

boolean customLoad(OpenJPAStateManager sm,
                   JDBCStore store,
                   PCState state,
                   JDBCFetchConfiguration fetch)
                   throws SQLException,
                          ClassNotFoundException

Implement this method to load the state of a given object, without a previous Result. Return true if this method handles the load. If the object does not exist in the data store, simply take no action on it (but still return true). Return false to use default loading.

Parameters:

state - if non-null, then you must initialize the state and persistent object of the given state manager (after determining the actual class of the object from the database, if there are possible persistent subclasses); initialization looks like this: sm.initialize (pcClass, state)

Throws:

SQLException

ClassNotFoundException

customLoad

boolean customLoad(OpenJPAStateManager sm,
                   JDBCStore store,
                   JDBCFetchConfiguration fetch,
                   Result result)
                   throws SQLException

Implement this method to customize loading from a Result into an instance. Return true if this mapping handles the load; false if normal loading should procede after calling this method.

Throws:

SQLException