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:

DB2PkGenerator, DerbyPkGenerator, 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

Modifier and Type	Method and Description
void	createAutoPk(DataNode node, List<DbEntity> dbEntities) Generates necessary database objects to provide automatic primary key support.
List<String>	createAutoPkStatements(List<DbEntity> dbEntities) Creates a list of CREATE SEQUENCE statements for the list of DbEntities.
protected String	createSequenceString(DbEntity ent)
void	dropAutoPk(DataNode node, List<DbEntity> dbEntities) Drops PK sequences for all specified DbEntities.
List<String>	dropAutoPkStatements(List<DbEntity> dbEntities) Creates a list of DROP SEQUENCE statements for the list of DbEntities.
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<String>	getExistingSequences(DataNode node) Fetches a list of existing sequences that might match Cayenne generated ones.
protected String	getSequencePrefix()
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	selectAllSequencesQuery()
protected String	selectNextValQuery(String pkGeneratingSequenceName)
protected String	sequenceName(DbEntity entity) Returns expected primary key sequence name for a DbEntity.

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<DbEntity> 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<String> createAutoPkStatements(List<DbEntity> dbEntities)

Creates a list of CREATE SEQUENCE statements for the list of DbEntities.

Specified by:

createAutoPkStatements in interface PkGenerator

Overrides:

createAutoPkStatements in class JdbcPkGenerator

dropAutoPk

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

Drops PK sequences for all specified DbEntities.

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<String> dropAutoPkStatements(List<DbEntity> dbEntities)

Creates a list of DROP SEQUENCE statements for the list of DbEntities.

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.

selectNextValQuery

protected String selectNextValQuery(String pkGeneratingSequenceName)

selectAllSequencesQuery

protected String selectAllSequencesQuery()

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.

getSequencePrefix

protected String getSequencePrefix()

getExistingSequences

protected List<String> getExistingSequences(DataNode node)
                                     throws SQLException

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

Throws:

SQLException