Module org.datanucleus.store.rdbms

Package org.datanucleus.store.rdbms.request

Class UpdateRequest

java.lang.Object

org.datanucleus.store.rdbms.request.Request

org.datanucleus.store.rdbms.request.UpdateRequest

public class UpdateRequest
extends Request

Class to provide a means of update of particular fields of a particular type in an RDBMS. Extends basic request class implementing the execute method to do a JDBC update operation. The SQL will be of the form

 UPDATE table-name SET param1=?, param2=?[, version=?] WHERE id1=? AND id2=?
 

or (when also performing version checks)

 UPDATE table-name SET param1=?, param2=?, version={newvers} WHERE id1=? AND id2=? AND version={oldvers}
 

Field Summary

Fields

Modifier and Type	Field	Description
protected org.datanucleus.metadata.AbstractClassMetaData	cmd	MetaData for the class.
protected boolean	versionChecks	Whether we should make checks on optimistic version before updating.
protected org.datanucleus.metadata.VersionMetaData	versionMetaData	MetaData for the version handling.

Fields inherited from class org.datanucleus.store.rdbms.request.Request

key, table

Constructor Summary

Constructors

Constructor	Description
UpdateRequest(DatastoreClass table, org.datanucleus.metadata.AbstractMemberMetaData[] reqFieldMetaData, org.datanucleus.metadata.AbstractClassMetaData cmd, org.datanucleus.ClassLoaderResolver clr)	Constructor, taking the table.
UpdateRequest(DatastoreClass table, org.datanucleus.metadata.AbstractMemberMetaData[] reqFieldMetaData, org.datanucleus.metadata.AbstractClassMetaData cmd, org.datanucleus.ClassLoaderResolver clr, BitSet nullPkFields, boolean noVersionUpdate)	Constructor, taking the table.

Method Summary

Modifier and Type	Method	Description
void	execute(org.datanucleus.state.DNStateManager sm)	Method performing the update of the record in the datastore.
boolean	willUpdate()	Check if update request will actually do any updates.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

cmd

protected org.datanucleus.metadata.AbstractClassMetaData cmd

MetaData for the class.

versionMetaData

protected org.datanucleus.metadata.VersionMetaData versionMetaData

MetaData for the version handling.

versionChecks

protected boolean versionChecks

Whether we should make checks on optimistic version before updating.

Constructor Detail

UpdateRequest

public UpdateRequest(DatastoreClass table,
                     org.datanucleus.metadata.AbstractMemberMetaData[] reqFieldMetaData,
                     org.datanucleus.metadata.AbstractClassMetaData cmd,
                     org.datanucleus.ClassLoaderResolver clr)

Constructor, taking the table. Uses the structure of the datastore table to build a basic query.

Parameters:

table - The Class Table representing the datastore table to update

reqFieldMetaData - MetaData of the fields to update

cmd - ClassMetaData of objects being updated

clr - ClassLoader resolver

UpdateRequest

public UpdateRequest(DatastoreClass table,
                     org.datanucleus.metadata.AbstractMemberMetaData[] reqFieldMetaData,
                     org.datanucleus.metadata.AbstractClassMetaData cmd,
                     org.datanucleus.ClassLoaderResolver clr,
                     BitSet nullPkFields,
                     boolean noVersionUpdate)

Constructor, taking the table. Uses the structure of the datastore table to build a basic query.

Parameters:

table - The Class Table representing the datastore table to update

reqFieldMetaData - MetaData of the fields to update

cmd - ClassMetaData of objects being updated

clr - ClassLoader resolver

nullPkFields - Fields in PK that are null - only used if PC model has objects with nullable PK fields

noVersionUpdate - Should we ignore updating version when using optimistic lock?

Method Detail

willUpdate

public boolean willUpdate()

Check if update request will actually do any updates.

Returns:

true if updates will be made, and return false if no updates will be made.

execute

public void execute(org.datanucleus.state.DNStateManager sm)

Method performing the update of the record in the datastore. Takes the constructed update query and populates with the specific record information.

Specified by:

execute in class Request

Parameters:

sm - StateManager for the record to be updated