org.apache.cayenne.query
Class BatchQuery

java.lang.Object
  extended by org.apache.cayenne.query.BatchQuery
All Implemented Interfaces:
Serializable, Query
Direct Known Subclasses:
DeleteBatchQuery, InsertBatchQuery, UpdateBatchQuery

public abstract class BatchQuery
extends Object
implements Query

BatchQuery and its descendants allow to group similar data for the batch database modifications, including inserts, updates and deletes. Single BatchQuery corresponds to a parameterized PreparedStatement and a matrix of values.

See Also:
Serialized Form

Field Summary
protected  int batchIndex
           
protected  DbEntity dbEntity
           
protected  String name
           
 
Constructor Summary
BatchQuery(DbEntity dbEntity)
           
 
Method Summary
 SQLAction createSQLAction(SQLActionVisitor visitor)
          Calls "batchAction" on the visitor.
abstract  List<DbAttribute> getDbAttributes()
          Returns a list of DbAttributes describing batch parameters.
 DbEntity getDbEntity()
          Returns a DbEntity associated with this batch.
 QueryMetadata getMetaData(EntityResolver resolver)
          Returns default select parameters.
 String getName()
          Returns a symbolic name of the query.
 ObjectId getObjectId()
          Returns an ObjectId associated with the current batch iteration.
abstract  Object getValue(int valueIndex)
          Returns a value at a given index for the current batch iteration.
protected  Object getValue(Map<String,Object> valueMap, DbAttribute attribute)
          A helper method used by subclasses to resolve deferred values on demand.
 boolean isEmpty()
          Returns true if this batch query has no parameter rows.
 boolean isUsingOptimisticLocking()
          Returns true if the batch query uses optimistic locking.
 boolean next()
          Repositions batch to the next object, so that subsequent calls to getObject(int) would return the values of the next batch object.
 void reset()
          Rewinds batch to the first parameter row.
 void route(QueryRouter router, EntityResolver resolver, Query substitutedQuery)
          A callback method invoked by Cayenne during the routing phase of the query execution.
 void setName(String name)
           
abstract  int size()
          Returns the number of parameter rows in a batch.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

batchIndex

protected int batchIndex
Since:
1.2

dbEntity

protected DbEntity dbEntity
Since:
1.2

name

protected String name
Constructor Detail

BatchQuery

public BatchQuery(DbEntity dbEntity)
Method Detail

getName

public String getName()
Description copied from interface: Query
Returns a symbolic name of the query. The name may be used as a key to find queries stored in the DataMap. Some query implementors reuse the name as a QueryMetadata cache key. Generally the name can be null.

Specified by:
getName in interface Query

setName

public void setName(String name)

getMetaData

public QueryMetadata getMetaData(EntityResolver resolver)
Returns default select parameters.

Specified by:
getMetaData in interface Query
Since:
1.2

route

public void route(QueryRouter router,
                  EntityResolver resolver,
                  Query substitutedQuery)
Description copied from interface: Query
A callback method invoked by Cayenne during the routing phase of the query execution. Mapping of DataNodes is provided by QueryRouter. Query should use a QueryRouter.route(QueryEngine, Query, Query) callback method to route itself. Query can create one or more substitute queries or even provide its own QueryEngine to execute itself.

Specified by:
route in interface Query
Since:
1.2

createSQLAction

public SQLAction createSQLAction(SQLActionVisitor visitor)
Calls "batchAction" on the visitor.

Specified by:
createSQLAction in interface Query
Since:
1.2

isUsingOptimisticLocking

public boolean isUsingOptimisticLocking()
Returns true if the batch query uses optimistic locking.

Since:
1.1

getDbEntity

public DbEntity getDbEntity()
Returns a DbEntity associated with this batch.


isEmpty

public boolean isEmpty()
Returns true if this batch query has no parameter rows.


getDbAttributes

public abstract List<DbAttribute> getDbAttributes()
Returns a list of DbAttributes describing batch parameters.


reset

public void reset()
Rewinds batch to the first parameter row.


next

public boolean next()
Repositions batch to the next object, so that subsequent calls to getObject(int) would return the values of the next batch object. Returns true if batch has more objects to iterate over, false otherwise.


getValue

public abstract Object getValue(int valueIndex)
Returns a value at a given index for the current batch iteration.

Since:
1.2

size

public abstract int size()
Returns the number of parameter rows in a batch.


getValue

protected Object getValue(Map<String,Object> valueMap,
                          DbAttribute attribute)
A helper method used by subclasses to resolve deferred values on demand. This is useful when a certain value comes from a generated key of another master object.

Since:
1.2

getObjectId

public ObjectId getObjectId()
Returns an ObjectId associated with the current batch iteration. Used internally by Cayenne to match current iteration with a specific object and assign it generated keys.

Default implementation simply returns null.

Since:
1.2


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