org.apache.openjpa.jdbc.meta
Interface FieldStrategy

All Superinterfaces:

Serializable, Strategy

All Known Subinterfaces:

LRSCollectionFieldStrategy, LRSMapFieldStrategy

All Known Implementing Classes:

AbstractFieldStrategy, ContainerFieldStrategy, EmbedFieldStrategy, FieldMapping, HandlerFieldStrategy, MapTableFieldStrategy, MaxEmbeddedBlobFieldStrategy, MaxEmbeddedByteArrayFieldStrategy, MaxEmbeddedCharArrayFieldStrategy, MaxEmbeddedClobFieldStrategy, NoneFieldStrategy, PrimitiveFieldStrategy, RelationCollectionInverseKeyFieldStrategy, RelationCollectionTableFieldStrategy, RelationFieldStrategy, RelationMapInverseKeyFieldStrategy, RelationMapTableFieldStrategy, RelationToManyInverseKeyFieldStrategy, RelationToManyTableFieldStrategy, StoreCollectionFieldStrategy, StringFieldStrategy

public interface FieldStrategy
extends Strategy

Maps a persistent field to the relational schema.

Since:

0.4.0

Author:

Abe White

Method Summary

void	appendIsEmpty(SQLBuffer sql, Select sel, Joins joins) Append a where clause to the given statement checking if this value is empty.
void	appendIsNotEmpty(SQLBuffer sql, Select sel, Joins joins) Append a where clause to the given statement checking if this value is not empty.
void	appendIsNotNull(SQLBuffer sql, Select sel, Joins joins) Append a where clause to the given statement checking if this value is not null.
void	appendIsNull(SQLBuffer sql, Select sel, Joins joins) Append a where clause to the given statement checking if this value is null.
void	appendSize(SQLBuffer sql, Select sel, Joins joins) Append a where clause to the given statement checking the size of the value.
boolean	isEagerSelectToMany() Whether the eager joins or selects used by this field are to-many.
boolean	isVersionable() Return true if this field can be used as part of a state image for optimistic locking.
Joins	join(Joins joins, boolean forceOuter) Join this value to the class table.
Joins	joinKey(Joins joins, boolean forceOuter) Join the key value to the class table.
Joins	joinKeyRelation(Joins joins, boolean forceOuter, boolean traverse) Join this value's table to the table for the related first class object key type, if any.
Joins	joinRelation(Joins joins, boolean forceOuter, boolean traverse) Join this value's table to the table for the related first class object type, if any.
void	load(OpenJPAStateManager sm, JDBCStore store, JDBCFetchConfiguration fetch) Load secondary data using a connection from the store manager.
void	load(OpenJPAStateManager sm, JDBCStore store, JDBCFetchConfiguration fetch, Result res) Load virtual row data; the given result is not guaranteed to contain data for this field, so the field mapping should make sure the result contains its needed column data before loading.
void	loadEagerJoin(OpenJPAStateManager sm, JDBCStore store, JDBCFetchConfiguration fetch, Result res) Load the joined eager result.
Object	loadEagerParallel(OpenJPAStateManager sm, JDBCStore store, JDBCFetchConfiguration fetch, Object res) Load the batched eager result.
Object	loadKeyProjection(JDBCStore store, JDBCFetchConfiguration fetch, Result res, Joins joins) Load this field's key value using the given result.
Object	loadProjection(JDBCStore store, JDBCFetchConfiguration fetch, Result res, Joins joins) Load this field value using the given result.
int	select(Select sel, OpenJPAStateManager sm, JDBCStore store, JDBCFetchConfiguration fetch, int eagerMode) Select the virtual row columns of this mapping.
void	selectEagerJoin(Select sel, OpenJPAStateManager sm, JDBCStore store, JDBCFetchConfiguration fetch, int eagerMode) Fill in joined select to related objects.
void	selectEagerParallel(SelectExecutor sel, OpenJPAStateManager sm, JDBCStore store, JDBCFetchConfiguration fetch, int eagerMode) Fill in parallel eager select for related objects.
void	setFieldMapping(FieldMapping owner) Set the class mapping using this strategy.
int	supportsSelect(Select sel, int type, OpenJPAStateManager sm, JDBCStore store, JDBCFetchConfiguration fetch) Return whether this mapping can perform the given select type.
Object	toDataStoreValue(Object val, JDBCStore store) Translate the given external field value to its datastore equivalent.
Object	toKeyDataStoreValue(Object val, JDBCStore store) Translate the given key value to its datastore equivalent.
void	where(OpenJPAStateManager sm, JDBCStore store, RowManager rm, Object prevValue) Add a WHERE condition to the row for this field such that the field's current DB value must equal the given previous value.

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

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

Method Detail

setFieldMapping

void setFieldMapping(FieldMapping owner)

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

supportsSelect

int supportsSelect(Select sel,
                   int type,
                   OpenJPAStateManager sm,
                   JDBCStore store,
                   JDBCFetchConfiguration fetch)

Return whether this mapping can perform the given select type. Return 0 if the given type is not supported. If the given type is an eager parallel type, return the number of UNIONed selects necessary to fetch the data. Otherwise, return any positive number if the type is supported. The given state manager may be null if selecting multiple instances.

See Also:

Select

selectEagerParallel

void selectEagerParallel(SelectExecutor sel,
                         OpenJPAStateManager sm,
                         JDBCStore store,
                         JDBCFetchConfiguration fetch,
                         int eagerMode)

Fill in parallel eager select for related objects.

See Also:

select(org.apache.openjpa.jdbc.sql.Select, org.apache.openjpa.kernel.OpenJPAStateManager, org.apache.openjpa.jdbc.kernel.JDBCStore, org.apache.openjpa.jdbc.kernel.JDBCFetchConfiguration, int)

selectEagerJoin

void selectEagerJoin(Select sel,
                     OpenJPAStateManager sm,
                     JDBCStore store,
                     JDBCFetchConfiguration fetch,
                     int eagerMode)

Fill in joined select to related objects.

See Also:

select(org.apache.openjpa.jdbc.sql.Select, org.apache.openjpa.kernel.OpenJPAStateManager, org.apache.openjpa.jdbc.kernel.JDBCStore, org.apache.openjpa.jdbc.kernel.JDBCFetchConfiguration, int)

isEagerSelectToMany

boolean isEagerSelectToMany()

Whether the eager joins or selects used by this field are to-many.

select

int select(Select sel,
           OpenJPAStateManager sm,
           JDBCStore store,
           JDBCFetchConfiguration fetch,
           int eagerMode)

Select the virtual row columns of this mapping.

Parameters:

sel - the select to add to

sm - the instance being loaded, or null if not initialized yet or selecting for multiple instances

store - the current store manager

fetch - fetch configuration

eagerMode - the eager fetch mode to use; this may be more restrictive than the mode of the fetch configuration

Returns:

> 0 if this mapping requires the selected data (if any), 0 if it selected data but does not require it, or < 0 if no data was selected

loadEagerParallel

Object loadEagerParallel(OpenJPAStateManager sm,
                         JDBCStore store,
                         JDBCFetchConfiguration fetch,
                         Object res)
                         throws SQLException

Load the batched eager result.

Parameters:

res - originally the Result to load from, but this method may return a processed result form that will be passed to subsequent calls

Throws:

SQLException

loadEagerJoin

void loadEagerJoin(OpenJPAStateManager sm,
                   JDBCStore store,
                   JDBCFetchConfiguration fetch,
                   Result res)
                   throws SQLException

Load the joined eager result.

Throws:

SQLException

load

void load(OpenJPAStateManager sm,
          JDBCStore store,
          JDBCFetchConfiguration fetch,
          Result res)
          throws SQLException

Load virtual row data; the given result is not guaranteed to contain data for this field, so the field mapping should make sure the result contains its needed column data before loading.

Throws:

SQLException

load

void load(OpenJPAStateManager sm,
          JDBCStore store,
          JDBCFetchConfiguration fetch)
          throws SQLException

Load secondary data using a connection from the store manager.

Throws:

SQLException

toDataStoreValue

Object toDataStoreValue(Object val,
                        JDBCStore store)

Translate the given external field value to its datastore equivalent. If the mapping occupies multiple columns in the datastore, return an object array, else return a single object. Simply returns the given object by default.

toKeyDataStoreValue

Object toKeyDataStoreValue(Object val,
                           JDBCStore store)

Translate the given key value to its datastore equivalent. If the mapping occupies multiple columns in the datastore, return an object array, else return a single object. Simply returns the given object by default.

appendIsEmpty

void appendIsEmpty(SQLBuffer sql,
                   Select sel,
                   Joins joins)

Append a where clause to the given statement checking if this value is empty. Appends impossible-to-satisfy SQL by default.

appendIsNotEmpty

void appendIsNotEmpty(SQLBuffer sql,
                      Select sel,
                      Joins joins)

Append a where clause to the given statement checking if this value is not empty. Appends always-satisfied SQL by default.

appendIsNull

void appendIsNull(SQLBuffer sql,
                  Select sel,
                  Joins joins)

Append a where clause to the given statement checking if this value is null.

appendIsNotNull

void appendIsNotNull(SQLBuffer sql,
                     Select sel,
                     Joins joins)

Append a where clause to the given statement checking if this value is not null.

appendSize

void appendSize(SQLBuffer sql,
                Select sel,
                Joins joins)

Append a where clause to the given statement checking the size of the value.

join

Joins join(Joins joins,
           boolean forceOuter)

Join this value to the class table. Does nothing by default.

joinKey

Joins joinKey(Joins joins,
              boolean forceOuter)

Join the key value to the class table. Does nothing by default.

joinRelation

Joins joinRelation(Joins joins,
                   boolean forceOuter,
                   boolean traverse)

Join this value's table to the table for the related first class object type, if any. Does nothing by default.

Parameters:

traverse - if true, throw proper exception if it is not possible for this mapping to traverse into the related type

joinKeyRelation

Joins joinKeyRelation(Joins joins,
                      boolean forceOuter,
                      boolean traverse)

Join this value's table to the table for the related first class object key type, if any. Does nothing by default.

Parameters:

traverse - if true, throw proper exception if it is not possible for this mapping to traverse into the related type

loadProjection

Object loadProjection(JDBCStore store,
                      JDBCFetchConfiguration fetch,
                      Result res,
                      Joins joins)
                      throws SQLException

Load this field value using the given result. The result will contain the columns from ValueMapping.getColumns().

Throws:

SQLException

loadKeyProjection

Object loadKeyProjection(JDBCStore store,
                         JDBCFetchConfiguration fetch,
                         Result res,
                         Joins joins)
                         throws SQLException

Load this field's key value using the given result. The result will contain the columns from ValueMapping.getColumns().

Throws:

SQLException

isVersionable

boolean isVersionable()

Return true if this field can be used as part of a state image for optimistic locking.

where

void where(OpenJPAStateManager sm,
           JDBCStore store,
           RowManager rm,
           Object prevValue)
           throws SQLException

Add a WHERE condition to the row for this field such that the field's current DB value must equal the given previous value. Only versionable mappings must implement this method meaningfully.

Throws:

SQLException