org.exolab.castor.jdo.engine
Class SQLQuery

java.lang.Object
  extended by org.exolab.castor.jdo.engine.SQLQuery
All Implemented Interfaces:
PersistenceQuery

public final class SQLQuery
extends java.lang.Object
implements PersistenceQuery

Since:
1.0
Version:
$Revision: 7951 $ $Date: 2006-04-11 15:26:07 -0600 (Tue, 11 Apr 2006) $
Author:
Assaf Arkin, Thomas Yip, Bruce Snyder, Werner Guttmann, Ralf Joachim

Method Summary
 boolean absolute(int row)
          Move to an absolute position within a ResultSet.
 void close()
          Close the query and release all resources held by the query.
 void execute(java.lang.Object conn, AccessMode accessMode, boolean scrollable)
          Execute the query with the give connection and lock type.
 void fetch(ProposedEntity proposedObject)
          Loades the object.
 java.lang.Class getResultType()
          Returns the type of object returned by this query.
 Identity nextIdentity(Identity identity)
          Returns the identity of the next object to be returned.
 void setParameter(int index, java.lang.Object value)
          Sets the value of a paramter.
 int size()
          Uses the underlying db's cursors to move to the last row in the result set, get the row number via getRow(), then move back to where ever the user was positioned in the resultset.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Method Detail

setParameter

public void setParameter(int index,
                         java.lang.Object value)
                  throws java.lang.ArrayIndexOutOfBoundsException,
                         java.lang.IllegalArgumentException
Description copied from interface: PersistenceQuery
Sets the value of a paramter. Will complain if the parameter is not of the specified type.

Specified by:
setParameter in interface PersistenceQuery
Parameters:
index - The parameter index
value - The parameter value
Throws:
java.lang.ArrayIndexOutOfBoundsException
java.lang.IllegalArgumentException

getResultType

public java.lang.Class getResultType()
Description copied from interface: PersistenceQuery
Returns the type of object returned by this query.

Specified by:
getResultType in interface PersistenceQuery
Returns:
The type of object returned by this query

absolute

public boolean absolute(int row)
                 throws PersistenceException
Move to an absolute position within a ResultSet. use the jdbc 2.0 method to move to an absolute position in the resultset.

Specified by:
absolute in interface PersistenceQuery
Parameters:
row - The row to move to
Returns:
True if the move was successful.
Throws:
PersistenceException - Indicates a problem in moving to an absolute position.

size

public int size()
         throws PersistenceException
Uses the underlying db's cursors to move to the last row in the result set, get the row number via getRow(), then move back to where ever the user was positioned in the resultset.

Specified by:
size in interface PersistenceQuery
Returns:
The size of the current result set.
Throws:
PersistenceException - If the excution of this method failed.

execute

public void execute(java.lang.Object conn,
                    AccessMode accessMode,
                    boolean scrollable)
             throws PersistenceException
Description copied from interface: PersistenceQuery
Execute the query with the give connection and lock type. After a successful return the query results will be returned by calling PersistenceQuery.nextIdentity(org.exolab.castor.persist.spi.Identity) and PersistenceQuery.fetch(org.castor.persist.ProposedEntity). The query parameters will be reset. A new query may be issued by providing new query parameters and calling PersistenceQuery.execute(Object, AccessMode, boolean).

Specified by:
execute in interface PersistenceQuery
Parameters:
conn - An open connection
accessMode - The access mode (null equals shared)
scrollable - The db cursor mode.
Throws:
PersistenceException - An invalid query or an error reported by the persistence engine.

nextIdentity

public Identity nextIdentity(Identity identity)
                      throws PersistenceException
Description copied from interface: PersistenceQuery
Returns the identity of the next object to be returned. Calling this method multiple time will skip objects. When the result set has been exhuasted, this method will return null.

Specified by:
nextIdentity in interface PersistenceQuery
Parameters:
identity - The identity of the previous object, null if this method is called for the first time
Returns:
The identity of the next object, null if the result set has been exhausted
Throws:
PersistenceException - An error reported by the persistence engine

close

public void close()
Description copied from interface: PersistenceQuery
Close the query and release all resources held by the query.

Specified by:
close in interface PersistenceQuery

fetch

public void fetch(ProposedEntity proposedObject)
           throws PersistenceException
Description copied from interface: PersistenceQuery
Loades the object. This method must be called immediately after PersistenceQuery.nextIdentity(org.exolab.castor.persist.spi.Identity) with the same identity.

If the object is locked by another transaction this method will block until the lock is released, or a timeout occured. If a timeout occurs or the object has been deleted by the other transaction, this method will report an ObjectNotFoundException. The query may proceed to the next identity.

This method is equivalent to Persistence.load(java.lang.Object, org.castor.persist.ProposedEntity, org.exolab.castor.persist.spi.Identity, org.exolab.castor.mapping.AccessMode) with a known cache engine and access mode and acts on the query results rather than issuing a new query to load the object.

Specified by:
fetch in interface PersistenceQuery
Parameters:
proposedObject - The fields to load into
Throws:
PersistenceException - The object was not found in persistent storage or any other persistence error occured.
See Also:
PersistenceQuery.fetch( org.castor.persist.ProposedEntity)


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