org.apache.cayenne.dba.oracle

Class OraclePkGenerator

java.lang.Object

org.apache.cayenne.dba.JdbcPkGenerator

org.apache.cayenne.dba.oracle.OraclePkGenerator

All Implemented Interfaces:

PkGenerator

Direct Known Subclasses:

H2PkGenerator, IngresPkGenerator, PostgresPkGenerator

public class OraclePkGenerator
extends JdbcPkGenerator

Sequence-based primary key generator implementation for Oracle. Uses Oracle sequences to generate primary key values. This approach is at least 50% faster when tested with Oracle compared to the lookup table approach.

When using Cayenne key caching mechanism, make sure that sequences in the database have "INCREMENT BY" greater or equal to OraclePkGenerator "pkCacheSize" property value. If this is not the case, you will need to adjust PkGenerator value accordingly. For example when sequence is incremented by 1 each time, use the following code:

 dataNode.getAdapter().getPkGenerator().setPkCacheSize(1);
 

Field Summary

Fields inherited from class org.apache.cayenne.dba.JdbcPkGenerator

adapter, DEFAULT_PK_CACHE_SIZE, pkCache, pkCacheSize, pkStartValue

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	OraclePkGenerator(JdbcAdapter adapter)

Method Summary

Methods

Modifier and Type	Method and Description
void	createAutoPk(DataNode node, List dbEntities) Generates necessary database objects to provide automatic primary key support.
List	createAutoPkStatements(List dbEntities) Returns a list of SQL strings needed to generates database objects to provide automatic primary support for the list of entities.
protected String	createSequenceString(DbEntity ent)
void	dropAutoPk(DataNode node, List dbEntities) Drops table named "AUTO_PK_SUPPORT" if it exists in the database.
List	dropAutoPkStatements(List dbEntities) Returns SQL string needed to drop database objects associated with automatic primary key generation.
protected String	dropSequenceString(DbEntity ent) Returns a SQL string needed to drop any database objects associated with automatic primary key generation process for a specific DbEntity.
protected List	getExistingSequences(DataNode node) Fetches a list of existing sequences that might match Cayenne generated ones.
protected long	longPkFromDatabase(DataNode node, DbEntity entity) Generates primary key by calling Oracle sequence corresponding to the dbEntity.
protected int	pkCacheSize(DbEntity entity)
protected String	sequenceName(DbEntity entity) Returns expected primary key sequence name for a DbEntity.
protected String	stripSchemaName(String sequenceName)

Methods inherited from class org.apache.cayenne.dba.JdbcPkGenerator

autoPkTableExists, dropAutoPkString, generatePk, getAdapter, getPkCacheSize, pkCreateString, pkDeleteString, pkSelectString, pkTableCreateString, pkUpdateString, reset, runUpdate, setPkCacheSize

Methods inherited from class java.lang.Object

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

Constructor Detail

OraclePkGenerator

protected OraclePkGenerator(JdbcAdapter adapter)

Method Detail

createAutoPk

public void createAutoPk(DataNode node,
                List dbEntities)
                  throws Exception

Description copied from interface: PkGenerator

Generates necessary database objects to provide automatic primary key support.

Specified by:

createAutoPk in interface PkGenerator

Overrides:

createAutoPk in class JdbcPkGenerator

Parameters:

node - node that provides access to a DataSource.

dbEntities - a list of entities that require primary key auto-generation support

Throws:

Exception

createAutoPkStatements

public List createAutoPkStatements(List dbEntities)

Description copied from interface: PkGenerator

Returns a list of SQL strings needed to generates database objects to provide automatic primary support for the list of entities. No actual database operations are performed.

Specified by:

createAutoPkStatements in interface PkGenerator

Overrides:

createAutoPkStatements in class JdbcPkGenerator

dropAutoPk

public void dropAutoPk(DataNode node,
              List dbEntities)
                throws Exception

Description copied from class: JdbcPkGenerator

Drops table named "AUTO_PK_SUPPORT" if it exists in the database.

Specified by:

dropAutoPk in interface PkGenerator

Overrides:

dropAutoPk in class JdbcPkGenerator

Parameters:

node - node that provides access to a DataSource.

dbEntities - a list of entities whose primary key auto-generation support should be dropped.

Throws:

Exception

dropAutoPkStatements

public List dropAutoPkStatements(List dbEntities)

Description copied from interface: PkGenerator

Returns SQL string needed to drop database objects associated with automatic primary key generation. No actual database operations are performed.

Specified by:

dropAutoPkStatements in interface PkGenerator

Overrides:

dropAutoPkStatements in class JdbcPkGenerator

createSequenceString

protected String createSequenceString(DbEntity ent)

dropSequenceString

protected String dropSequenceString(DbEntity ent)

Returns a SQL string needed to drop any database objects associated with automatic primary key generation process for a specific DbEntity.

longPkFromDatabase

protected long longPkFromDatabase(DataNode node,
                      DbEntity entity)
                           throws Exception

Generates primary key by calling Oracle sequence corresponding to the dbEntity. Executed SQL looks like this:

   SELECT pk_table_name.nextval FROM DUAL
 

Overrides:

longPkFromDatabase in class JdbcPkGenerator

Throws:

Exception

Since:

3.0

pkCacheSize

protected int pkCacheSize(DbEntity entity)

sequenceName

protected String sequenceName(DbEntity entity)

Returns expected primary key sequence name for a DbEntity.

stripSchemaName

protected String stripSchemaName(String sequenceName)

getExistingSequences

protected List getExistingSequences(DataNode node)
                             throws SQLException

Fetches a list of existing sequences that might match Cayenne generated ones.

Throws:

SQLException