oracle.jbo.server
Interface Entity

All Known Implementing Classes:

EntityImpl

public interface Entity

extends Row, ValidationListener, ValidationManager, oracle.jbo.server.TransactionManager, TransactionListener, TransactionPostListener

Defines the middle-tier representation of database rows.

An Entity Object provides an object-oriented representation of the data it caches from a database object, such as a table or view. Database rows are presented as individual Entity Objects, in which attributes typically correspond to columns in the corresponding table.

The status of an Entity Object, relative to the corresponding database data, is indicated by its current post-state and entity-state.

States are set to one of STATUS_NEW, STATUS_MODIFIED, STATUS_DELETED and STATUS_DEAD by create, update, delete, and rollback operations, respectively. These operations can set both the post-state and the entity-state.

Post-states indicate the state of the Entity Object's data relative to the transaction's corresponding database data. The post-state is reset to STATUS_UNMODIFIED when a post operation is invoked.

Entity-states indicate the state of the Entity Object's data relative to the actual database data, and the state of the transaction itself. The entity-state is reset to STATUS_UNMODIFIED by a commit or a rollback operation.

Since:

JDeveloper 3.0

Field Summary

static byte	STATUS_DEAD Indicates that the Entity Object is a new row that has been discarded.
static byte	STATUS_DELETED Indicates that the Entity Object's row has been deleted.
static byte	STATUS_MODIFIED Indicates that the Entity Object's row is changed.
static byte	STATUS_NEW Indicates that the Entity Object's row is newly created.
static byte	STATUS_UNMODIFIED Indicates that the Entity Object's row is unchanged or has been updated.

Fields inherited from interface oracle.jbo.XMLInterface

XML_OPT_CHANGES_ONLY, XML_OPT_LIMIT_RANGE

Method Summary

byte	getEntityState() Gets this Entity Object's current entity-state.
byte	getPostState() Gets this Entity Object's current post-state.
Key	getPrimaryKey() Returns the primay key for this Entity Object's row.
boolean	isLocked() Gets the status of the Entity Object's lock.
boolean	isValid() Returns the state of this Entity Object's validity flag.
void	revert() Reverts this Entity Object's row to the database's values.

Methods inherited from interface oracle.jbo.Row

getKey, isAttributeUpdateable, lock, remove, validate

Methods inherited from interface oracle.jbo.server.ValidationManager

addToValidationListeners

Methods inherited from interface oracle.jbo.server.TransactionManager

addTransactionPostListener, addTransactionPostListenerNoCheck, removeTransactionPostListener

Methods inherited from interface oracle.jbo.server.TransactionListener

afterCommit, afterRemove, afterRollback, beforeCommit, beforeRollback, isTransientTransactionListener

Methods inherited from interface oracle.jbo.server.TransactionPostListener

getTransPostHandle, isTransientTransactionPostListener, postChanges, setTransPostHandle

Methods inherited from interface oracle.jbo.AttributeList

getAttribute, getAttribute, getAttributeCount, getAttributeIndexOf, setAttribute, setAttribute

Methods inherited from interface oracle.jbo.XMLInterface

readXML, readXML, writeXML, writeXML

Field Detail

STATUS_NEW

public static final byte STATUS_NEW

Indicates that the Entity Object's row is newly created.

STATUS_UNMODIFIED

public static final byte STATUS_UNMODIFIED

Indicates that the Entity Object's row is unchanged or has been updated.

STATUS_MODIFIED

public static final byte STATUS_MODIFIED

Indicates that the Entity Object's row is changed.

STATUS_DELETED

public static final byte STATUS_DELETED

Indicates that the Entity Object's row has been deleted.

STATUS_DEAD

public static final byte STATUS_DEAD

Indicates that the Entity Object is a new row that has been discarded.

Method Detail

isValid

public boolean isValid()

Returns the state of this Entity Object's validity flag. This predecate does not perform a validity test.

An Entity Object is marked valid if it has been validated and not subsequently modified or set invalid.

Specified by:

isValid in interface ValidationListener

Returns:

true if this Entity Object has been validated.

getPrimaryKey

public Key getPrimaryKey()

Returns the primay key for this Entity Object's row. For example, if you are comparing two Entity Objects, you can compare the keys instead of comparing the Entities.

Typically, this method should not be overridden.

Returns:

the primary key.

isLocked

public boolean isLocked()

Gets the status of the Entity Object's lock.

An Entity Object is locked if its corresponding database row is locked. This method should not be overridden.

Returns:

true if this Entity Object is locked.

getEntityState

public byte getEntityState()

Gets this Entity Object's current entity-state. An Entity Object's state can be one of:

• STATUS_UNMODIFIED - if this Entity Object originated in the database and is unmodified, or if modifications have been committed to the database.
• STATUS_MODIFIED - if this Entity Object originated in the database, and has been modified in the current transaction.
• STATUS_NEW - if this Entity Object is new in the current transaction.
• STATUS_DELETED - if this Entity Object has been deleted in the current transaction.
• STATUS_DEAD - if this Entity Object is new in the current transaction and has been deleted.

Returns:

one of STATUS_UNMODIFIED, STATUS_MODIFIED, STATUS_NEW, STATUS_DELETED, or STATUS_DEAD

getPostState

public byte getPostState()

Gets this Entity Object's current post-state. The current post state can be one of:

• STATUS_UNMODIFIED - if this Entity Object has been queried from the database and is unchanged, or if it has been posted to the database.
• STATUS_MODIFIED - if this Entity Object has been queried from the database and has changed.
• STATUS_NEW - if this Entity Object is new and not yet posted to the database.
• STATUS_DELETED - if this Entity Object has been marked for deletion.
• STATUS_DEAD - if this Entity Object is new, but has been deleted.

Returns:

one of STATUS_UNMODIFIED, STATUS_MODIFIED, STATUS_NEW, STATUS_DELETED, or STATUS_DEAD

revert

public void revert()

Reverts this Entity Object's row to the database's values.

Calling this method will either reset the attribute values to their database values or revert them to their default values. If the Entity Object is posted, all the attributes revert to the to unread state, so that a subsequent EntityImpl.getAttribute(int index) call will refresh all attributes from the database.

See Also:

EntityImpl.getAttribute(int index)