org.apache.derby.iapi.sql.dictionary
Class TriggerDescriptor

java.lang.Object
  org.apache.derby.iapi.sql.dictionary.TupleDescriptor
      org.apache.derby.iapi.sql.dictionary.TriggerDescriptor

All Implemented Interfaces:

java.io.Externalizable, java.io.Serializable, Dependable, Formatable, TypedFormat, Dependent, Provider, UniqueSQLObjectDescriptor, UniqueTupleDescriptor

public class TriggerDescriptor
extends TupleDescriptor
implements UniqueSQLObjectDescriptor, Provider, Dependent, Formatable

A trigger.

We are dependent on TableDescriptors, SPSDescriptors (for our WHEN clause and our action). Note that we don't strictly need to be dependent on out SPSes because we could just disallow anyone from dropping an sps of type 'T', but to keep dependencies uniform, we'll do be dependent.

We are a provider for DML (PreparedStatements or SPSes) The public methods for this class are:

1. getUUID
2. getName
3. getSchemaDescriptor
4. public boolean listensForEvent(int event);
5. public int getTriggerEventMask();
6. public Timestamp getCreationTimestamp();
7. public boolean isBeforeTrigger();
8. public boolean isRowTrigger();
9. public UUID getActionId();
10. public SPSDescriptor getActionSPS();
11. public UUID getWhenClauseId();
12. public SPSDescriptor getWhenClauseSPS()
13. public TableDescriptor getTableDescriptor()
14. public ReferencedColumns getReferencedColumnsDescriptor()
15. public int[] getReferencedCols();
16. public int[] getReferencedColsInTriggerAction();
17. public boolean isEnabled();
18. public void setEnabled();
19. public void setDisabled();
20. public boolean needsToFire(int stmtType, int[] modifiedCols)
21. public String getTriggerDefinition();
22. public boolean getReferencingOld();
23. public boolean getReferencingNew();
24. public String getOldReferencingName();
25. public String getNewReferencingName();

See Also:

Serialized Form

Field Summary

private SPSDescriptor	actionSPS
private UUID	actionSPSId
private java.sql.Timestamp	creationTimestamp
private int	eventMask
private UUID	id
private boolean	isBefore
private boolean	isEnabled
private boolean	isRow
private java.lang.String	name
private java.lang.String	newReferencingName
private java.lang.String	oldReferencingName
private int[]	referencedCols
private int[]	referencedColsInTriggerAction
private boolean	referencingNew
private boolean	referencingOld
private SchemaDescriptor	sd
static int	SYSTRIGGERS_STATE_FIELD
private TableDescriptor	td
static int	TRIGGER_EVENT_DELETE
static int	TRIGGER_EVENT_INSERT
static int	TRIGGER_EVENT_UPDATE
private java.lang.String	triggerDefinition
private UUID	triggerSchemaId
private UUID	triggerTableId
private SPSDescriptor	whenSPS
private UUID	whenSPSId

Fields inherited from interface org.apache.derby.catalog.Dependable

ACTIVATION, ALIAS, COLUMNS_IN_TABLE, COLUMNS_PERMISSION, CONGLOMERATE, CONSTRAINT, DEFAULT, FILE, HEAP, INDEX, PERM, PREPARED_STATEMENT, ROLE_GRANT, ROUTINE_PERMISSION, SCHEMA, SEQUENCE, STORED_PREPARED_STATEMENT, TABLE, TABLE_PERMISSION, TRIGGER, VIEW

Constructor Summary

TriggerDescriptor()
Niladic constructor, for formatable

TriggerDescriptor(DataDictionary dataDictionary, SchemaDescriptor sd, UUID id, java.lang.String name, int eventMask, boolean isBefore, boolean isRow, boolean isEnabled, TableDescriptor td, UUID whenSPSId, UUID actionSPSId, java.sql.Timestamp creationTimestamp, int[] referencedCols, int[] referencedColsInTriggerAction, java.lang.String triggerDefinition, boolean referencingOld, boolean referencingNew, java.lang.String oldReferencingName, java.lang.String newReferencingName)
Constructor.

Method Summary

void	drop(LanguageConnectionContext lcc)
UUID	getActionId() Get the trigger action sps UUID
SPSDescriptor	getActionSPS(LanguageConnectionContext lcc) Get the trigger action sps from SYSSTATEMENTS.
java.lang.String	getClassType() Get the provider's type.
java.sql.Timestamp	getCreationTimestamp() Get the time that this trigger was created.
protected DataDictionary	getDataDictionary()
DependableFinder	getDependableFinder() Get an object which can be written to disk and which, when read from disk, will find or reconstruct this in-memory Dependable.
java.lang.String	getDescriptorName()
java.lang.String	getDescriptorType() Each descriptor must identify itself with its type; i.e index, check constraint whatever.
java.lang.String	getName() Get the trigger name
java.lang.String	getNewReferencingName() Get the new Referencing name, if any, from the REFERENCING clause.
UUID	getObjectID() Get the provider's UUID
java.lang.String	getObjectName() Return the name of this Provider.
java.lang.String	getOldReferencingName() Get the old Referencing name, if any, from the REFERENCING clause.
int[]	getReferencedCols() Get the referenced column array for this trigger, used in "alter table drop column", we get the handle and change it
int[]	getReferencedColsInTriggerAction() Get the referenced column array for the trigger action columns.
boolean	getReferencingNew() Get whether or not NEW was replaced in the REFERENCING clause.
boolean	getReferencingOld() Get whether or not OLD was replaced in the REFERENCING clause.
SchemaDescriptor	getSchemaDescriptor() Get the triggers schema descriptor
TableDescriptor	getTableDescriptor() Get the trigger table descriptor
UUID	getTableId()
java.lang.String	getTriggerDefinition() Get the original trigger definition.
int	getTriggerEventMask() Get the trigger event mask.
int	getTypeFormatId() Get the formatID which corresponds to this class.
UUID	getUUID() Get the trigger UUID
UUID	getWhenClauseId() Get the trigger when clause sps UUID
SPSDescriptor	getWhenClauseSPS() Get the trigger when clause sps
boolean	isBeforeTrigger() Is this a before trigger
boolean	isEnabled() Is this trigger enabled
boolean	isRowTrigger() Is this a row trigger
boolean	isValid() Check that all of the dependent's dependencies are valid.
boolean	listensForEvent(int event) Indicate whether this trigger listens for this type of event.
void	makeInvalid(int action, LanguageConnectionContext lcc) Mark the dependent as invalid (due to at least one of its dependencies being invalid).
boolean	needsToFire(int stmtType, int[] modifiedCols) Does this trigger need to fire on this type of DML?
void	prepareToInvalidate(Provider p, int action, LanguageConnectionContext lcc) Prepare to mark the dependent as invalid (due to at least one of its dependencies being invalid).
void	readExternal(java.io.ObjectInput in) Read this object from a stream of stored objects.
void	setDisabled() Mark this trigger as disabled
void	setEnabled() Mark this trigger as enabled
java.lang.String	toString()
void	writeExternal(java.io.ObjectOutput out) Write this object to a stream of stored objects.

Methods inherited from class org.apache.derby.iapi.sql.dictionary.TupleDescriptor

getColumnDependableFinder, getDependableFinder, isPersistent, setDataDictionary

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.derby.catalog.Dependable

isPersistent

Field Detail

SYSTRIGGERS_STATE_FIELD

public static final int SYSTRIGGERS_STATE_FIELD

See Also:

Constant Field Values

TRIGGER_EVENT_UPDATE

public static final int TRIGGER_EVENT_UPDATE

See Also:

Constant Field Values

TRIGGER_EVENT_DELETE

public static final int TRIGGER_EVENT_DELETE

See Also:

Constant Field Values

TRIGGER_EVENT_INSERT

public static final int TRIGGER_EVENT_INSERT

See Also:

Constant Field Values

id

private UUID id

name

private java.lang.String name

oldReferencingName

private java.lang.String oldReferencingName

newReferencingName

private java.lang.String newReferencingName

triggerDefinition

private java.lang.String triggerDefinition

sd

private SchemaDescriptor sd

eventMask

private int eventMask

isBefore

private boolean isBefore

isRow

private boolean isRow

referencingOld

private boolean referencingOld

referencingNew

private boolean referencingNew

td

private TableDescriptor td

actionSPSId

private UUID actionSPSId

actionSPS

private SPSDescriptor actionSPS

whenSPSId

private UUID whenSPSId

whenSPS

private SPSDescriptor whenSPS

isEnabled

private boolean isEnabled

referencedCols

private int[] referencedCols

referencedColsInTriggerAction

private int[] referencedColsInTriggerAction

creationTimestamp

private java.sql.Timestamp creationTimestamp

triggerSchemaId

private UUID triggerSchemaId

triggerTableId

private UUID triggerTableId

Constructor Detail

TriggerDescriptor

public TriggerDescriptor()

Niladic constructor, for formatable

TriggerDescriptor

public TriggerDescriptor(DataDictionary dataDictionary,
                         SchemaDescriptor sd,
                         UUID id,
                         java.lang.String name,
                         int eventMask,
                         boolean isBefore,
                         boolean isRow,
                         boolean isEnabled,
                         TableDescriptor td,
                         UUID whenSPSId,
                         UUID actionSPSId,
                         java.sql.Timestamp creationTimestamp,
                         int[] referencedCols,
                         int[] referencedColsInTriggerAction,
                         java.lang.String triggerDefinition,
                         boolean referencingOld,
                         boolean referencingNew,
                         java.lang.String oldReferencingName,
                         java.lang.String newReferencingName)

Constructor. Used when creating a trigger from SYS.SYSTRIGGERS

Parameters:

dataDictionary - the data dictionary

sd - the schema descriptor for this trigger

id - the trigger id

name - the trigger name

eventMask - TriggerDescriptor.TRIGGER_EVENT_XXXX

isBefore - is this a before (as opposed to after) trigger

isRow - is this a row trigger or statement trigger

isEnabled - is this trigger enabled or disabled

td - the table upon which this trigger is defined

whenSPSId - the sps id for the when clause (may be null)

actionSPSId - the spsid for the trigger action (may be null)

creationTimestamp - when was this trigger created?

referencedCols - what columns does this trigger reference (may be null)

referencedColsInTriggerAction - what columns does the trigger action reference through old/new transition variables (may be null)

triggerDefinition - The original user text of the trigger action

referencingOld - whether or not OLD appears in REFERENCING clause

referencingNew - whether or not NEW appears in REFERENCING clause

oldReferencingName - old referencing table name, if any, that appears in REFERCING clause

newReferencingName - new referencing table name, if any, that appears in REFERCING clause

Method Detail

getUUID

public UUID getUUID()

Get the trigger UUID

Specified by:

getUUID in interface UniqueTupleDescriptor

Returns:

the id

getName

public java.lang.String getName()

Get the trigger name

Specified by:

getName in interface UniqueSQLObjectDescriptor

Returns:

the name

getTableId

public UUID getTableId()

getSchemaDescriptor

public SchemaDescriptor getSchemaDescriptor()
                                     throws StandardException

Get the triggers schema descriptor

Specified by:

getSchemaDescriptor in interface UniqueSQLObjectDescriptor

Returns:

the schema descriptor

Throws:

StandardException - on error

listensForEvent

public boolean listensForEvent(int event)

Indicate whether this trigger listens for this type of event.

Parameters:

event - TRIGGER_EVENT_XXXX

Returns:

true if it listens to the specified event.

getTriggerEventMask

public int getTriggerEventMask()

Get the trigger event mask. Currently, a trigger may only listen for a single event, though it may OR multiple events in the future.

Returns:

the trigger event mask

getCreationTimestamp

public java.sql.Timestamp getCreationTimestamp()

Get the time that this trigger was created.

Returns:

the time the trigger was created

isBeforeTrigger

public boolean isBeforeTrigger()

Is this a before trigger

Returns:

true if it is a before trigger

isRowTrigger

public boolean isRowTrigger()

Is this a row trigger

Returns:

true if it is a before trigger

getActionId

public UUID getActionId()

Get the trigger action sps UUID

Returns:

the uuid of the sps action

getActionSPS

public SPSDescriptor getActionSPS(LanguageConnectionContext lcc)
                           throws StandardException

Get the trigger action sps from SYSSTATEMENTS. If we find that the sps is invalid and the trigger is defined at row level and it has OLD/NEW transient variables through REFERENCES clause, then the sps from SYSSTATEMENTS may not be valid anymore. In such a case, we regenerate the trigger action sql and use that for the sps and update SYSSTATEMENTS using this new sps. This update of SYSSTATEMENTS was introduced with DERBY-4874

Parameters:

lcc - The LanguageConnectionContext to use.

Returns:

the trigger action sps

Throws:

StandardException - on error

getWhenClauseId

public UUID getWhenClauseId()

Get the trigger when clause sps UUID

Returns:

the uuid of the sps action

getWhenClauseSPS

public SPSDescriptor getWhenClauseSPS()
                               throws StandardException

Get the trigger when clause sps

Returns:

the sps of the when clause

Throws:

StandardException - on error

getTableDescriptor

public TableDescriptor getTableDescriptor()
                                   throws StandardException

Get the trigger table descriptor

Returns:

the table descripor upon which this trigger is declared

Throws:

StandardException - on error

getReferencedCols

public int[] getReferencedCols()

Get the referenced column array for this trigger, used in "alter table drop column", we get the handle and change it

Returns:

the referenced column array

getReferencedColsInTriggerAction

public int[] getReferencedColsInTriggerAction()

Get the referenced column array for the trigger action columns.

Returns:

the referenced column array

isEnabled

public boolean isEnabled()

Is this trigger enabled

Returns:

true if it is enabled

setEnabled

public void setEnabled()

Mark this trigger as enabled

setDisabled

public void setDisabled()

Mark this trigger as disabled

needsToFire

public boolean needsToFire(int stmtType,
                           int[] modifiedCols)
                    throws StandardException

Does this trigger need to fire on this type of DML?

Parameters:

stmtType - the type of DML (StatementType.INSERT|StatementType.UPDATE|StatementType.DELETE)

modifiedCols - the columns modified, or null for all

Returns:

true/false

Throws:

StandardException - on error

getTriggerDefinition

public java.lang.String getTriggerDefinition()

Get the original trigger definition.

Returns:

The trigger definition.

getReferencingOld

public boolean getReferencingOld()

Get whether or not OLD was replaced in the REFERENCING clause.

Returns:

Whether or not OLD was replaced in the REFERENCING clause.

getReferencingNew

public boolean getReferencingNew()

Get whether or not NEW was replaced in the REFERENCING clause.

Returns:

Whether or not NEW was replaced in the REFERENCING clause.

getOldReferencingName

public java.lang.String getOldReferencingName()

Get the old Referencing name, if any, from the REFERENCING clause.

Returns:

The old Referencing name, if any, from the REFERENCING clause.

getNewReferencingName

public java.lang.String getNewReferencingName()

Get the new Referencing name, if any, from the REFERENCING clause.

Returns:

The new Referencing name, if any, from the REFERENCING clause.

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

getDependableFinder

public DependableFinder getDependableFinder()

Description copied from interface: Dependable

Get an object which can be written to disk and which, when read from disk, will find or reconstruct this in-memory Dependable.

Specified by:

getDependableFinder in interface Dependable

Returns:

the stored form of this provider

See Also:

Dependable.getDependableFinder()

getObjectName

public java.lang.String getObjectName()

Return the name of this Provider. (Useful for errors.)

Specified by:

getObjectName in interface Dependable

Returns:

String The name of this provider.

getObjectID

public UUID getObjectID()

Get the provider's UUID

Specified by:

getObjectID in interface Dependable

Returns:

The provider's UUID

getClassType

public java.lang.String getClassType()

Get the provider's type.

Specified by:

getClassType in interface Dependable

Returns:

char The provider's type.

isValid

public boolean isValid()

Check that all of the dependent's dependencies are valid.

Specified by:

isValid in interface Dependent

Returns:

true if the dependent is currently valid

prepareToInvalidate

public void prepareToInvalidate(Provider p,
                                int action,
                                LanguageConnectionContext lcc)
                         throws StandardException

Prepare to mark the dependent as invalid (due to at least one of its dependencies being invalid).

Specified by:

prepareToInvalidate in interface Dependent

Parameters:

action - The action causing the invalidation

p - the provider

lcc - the language connection context

Throws:

StandardException - thrown if unable to make it invalid

makeInvalid

public void makeInvalid(int action,
                        LanguageConnectionContext lcc)
                 throws StandardException

Mark the dependent as invalid (due to at least one of its dependencies being invalid). Always an error for a trigger -- should never have gotten here.

Specified by:

makeInvalid in interface Dependent

Parameters:

lcc - the language connection context

action - The action causing the invalidation

Throws:

StandardException - thrown if called in sanity mode

drop

public void drop(LanguageConnectionContext lcc)
          throws StandardException

Throws:

StandardException

readExternal

public void readExternal(java.io.ObjectInput in)
                  throws java.io.IOException,
                         java.lang.ClassNotFoundException

Read this object from a stream of stored objects.

Specified by:

readExternal in interface java.io.Externalizable

Parameters:

in - read this.

Throws:

java.io.IOException - thrown on error

java.lang.ClassNotFoundException - thrown on error

getDataDictionary

protected DataDictionary getDataDictionary()

Overrides:

getDataDictionary in class TupleDescriptor

writeExternal

public void writeExternal(java.io.ObjectOutput out)
                   throws java.io.IOException

Write this object to a stream of stored objects.

Specified by:

writeExternal in interface java.io.Externalizable

Parameters:

out - write bytes here.

Throws:

java.io.IOException - thrown on error

getTypeFormatId

public int getTypeFormatId()

Get the formatID which corresponds to this class.

Specified by:

getTypeFormatId in interface TypedFormat

Returns:

the formatID of this class

getDescriptorType

public java.lang.String getDescriptorType()

Description copied from class: TupleDescriptor

Each descriptor must identify itself with its type; i.e index, check constraint whatever.

Overrides:

getDescriptorType in class TupleDescriptor

See Also:

TupleDescriptor.getDescriptorType()

getDescriptorName

public java.lang.String getDescriptorName()

Overrides:

getDescriptorName in class TupleDescriptor

See Also:

TupleDescriptor.getDescriptorName()