Class LocateRequest

java.lang.Object

org.datanucleus.store.rdbms.request.Request

org.datanucleus.store.rdbms.request.LocateRequest

public class LocateRequest
extends Request

Request to locate a record in the data store. Performs an SQL statement like

SELECT 1 FROM CANDIDATE_TABLE WHERE ID = ?

and checks if the ResultSet is empty

Field Summary

Fields

Modifier and Type	Field	Description
private StatementClassMapping	mappingDefinition	Definition of mappings in the SQL statement.
private String	statementLocked	JDBC locate statement with locking.
private String	statementUnlocked	JDBC locate statement without locking.

Fields inherited from class Request

key, table

Constructor Summary

Constructors

Constructor	Description
LocateRequest(DatastoreClass table, org.datanucleus.metadata.AbstractClassMetaData cmd, org.datanucleus.ClassLoaderResolver clr)	Constructor, taking the table.

Method Summary

Modifier and Type	Method	Description
void	execute(org.datanucleus.state.DNStateManager sm)	Method performing the retrieval of the record from the datastore.

Methods inherited from class Object

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

Field Details

statementUnlocked

private String statementUnlocked

JDBC locate statement without locking.

statementLocked

private String statementLocked

JDBC locate statement with locking.

mappingDefinition

private StatementClassMapping mappingDefinition

Definition of mappings in the SQL statement.

Constructor Details

LocateRequest

public LocateRequest(DatastoreClass table,
 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 retrieve

cmd - Metadata for the class we are locating an instance of

clr - ClassLoader resolver

Method Details

execute

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

Method performing the retrieval of the record from the datastore. Takes the constructed retrieval query and populates with the specific record information.

Specified by:

execute in class Request

Parameters:

sm - StateManager for the record to be retrieved