Overview  Package   Class  Use  Deprecated  Index
Home >> All >> org >> apache >> derby >> impl >> sql >> [ execute overview ]	PREV CLASS  NEXT CLASS
SUMMARY:  JAVADOC |  SOURCE |  DOWNLOAD | NESTED | FIELD | CONSTR | METHOD	DETAIL: FIELD | CONSTR | METHOD

---

org.apache.derby.impl.sql.execute
Class InternalTriggerExecutionContext  

java.lang.Object
  org.apache.derby.impl.sql.execute.InternalTriggerExecutionContext

All Implemented Interfaces:

org.apache.derby.iapi.sql.execute.ExecutionStmtValidator, org.apache.derby.iapi.db.TriggerExecutionContext

---

public class InternalTriggerExecutionContext

extends java.lang.Object

implements org.apache.derby.iapi.db.TriggerExecutionContext, org.apache.derby.iapi.sql.execute.ExecutionStmtValidator

There is one of these beasts per INSERT/DELETE/UPDATE statement. It fulfills the contract for the externally visible trigger execution context and it validates that a statement that is about to be executed doesn't violate the restrictions placed upon what can be executed from a trigger.

Note that it is crucial that cleanup() is called once the DML has completed, cleanup() makes sure that users can't do something invalid on a tec reference that they were holding from when the trigger fired.

---

Field Summary
protected  org.apache.derby.iapi.sql.execute.CursorResultSet	afterResultSet
protected  org.apache.derby.iapi.sql.execute.ExecRow	afterRow           used exclusively for InsertResultSets which have autoincrement columns.
private  java.util.Vector	aiCounters           aiCounters is a vector of AutoincrementCounters used to keep state which might be used by the trigger.
private  java.util.Hashtable	aiHT           aiHT is a hashtable of autincrement pairs.
protected  org.apache.derby.iapi.sql.execute.CursorResultSet	beforeResultSet
protected  org.apache.derby.iapi.jdbc.ConnectionContext	cc
protected  int[]	changedColIds
protected  java.lang.String[]	changedColNames
protected  boolean	cleanupCalled
protected  int	dmlType
protected  TriggerEvent	event
protected  org.apache.derby.iapi.sql.conn.LanguageConnectionContext	lcc
private  java.util.Vector	resultSetVector
protected  java.lang.String	statementText
protected  org.apache.derby.catalog.UUID	targetTableId
protected  java.lang.String	targetTableName
protected  org.apache.derby.iapi.sql.dictionary.TriggerDescriptor	triggerd

 

Fields inherited from interface org.apache.derby.iapi.db.TriggerExecutionContext

DELETE_EVENT, INSERT_EVENT, UPDATE_EVENT

 

Constructor Summary

InternalTriggerExecutionContext(org.apache.derby.iapi.sql.conn.LanguageConnectionContext lcc, org.apache.derby.iapi.jdbc.ConnectionContext cc, java.lang.String statementText, int dmlType, int[] changedColIds, java.lang.String[] changedColNames, org.apache.derby.catalog.UUID targetTableId, java.lang.String targetTableName, java.util.Vector aiCounters)           Build me a big old nasty trigger execution context.

 

Method Summary
protected  void	cleanup()           Cleanup the trigger execution context.
(package private)  void	clearCurrentTriggerEvent()
(package private)  void	clearTrigger()
void	copyHashtableToAIHT(java.util.Hashtable from)           Copy a hashtable of autoincrement values into the trigger execution context hashtable of autoincrement values.
private  void	ensureProperContext()           Make sure that the user isn't trying to get a result set after we have cleaned up.
java.lang.Long	getAutoincrementValue(java.lang.String identity)
java.lang.String	getEventStatementText()           Get the text of the statement that caused the trigger to fire.
int	getEventType()           Get the type for the event that caused the trigger to fire.
java.lang.String[]	getModifiedColumns()           Get the columns that have been modified by the statement that caused this trigger to fire.
java.sql.ResultSet	getNewRow()           Like getAfterResultSet(), but returns a result set positioned on the first row of the before result set.
java.sql.ResultSet	getNewRowSet()           Returns a result set row the new images of the changed rows.
java.sql.ResultSet	getOldRow()           Like getBeforeResultSet(), but returns a result set positioned on the first row of the before result set.
java.sql.ResultSet	getOldRowSet()           Returns a result set row the old images of the changed rows.
org.apache.derby.catalog.UUID	getTargetTableId()           Get the target table UUID upon which the trigger event is declared.
java.lang.String	getTargetTableName()           Get the target table name upon which the trigger event is declared.
void	resetAICounters(boolean begin)           Reset Autoincrement counters to the beginning or the end.
(package private)  void	setAfterResultSet(org.apache.derby.iapi.sql.execute.CursorResultSet rs)
(package private)  void	setBeforeResultSet(org.apache.derby.iapi.sql.execute.CursorResultSet rs)
(package private)  void	setCurrentTriggerEvent(TriggerEvent event)
(package private)  void	setTrigger(org.apache.derby.iapi.sql.dictionary.TriggerDescriptor triggerd)
java.lang.String	toString()           Convert this Object to a human-readable String.
void	updateAICounters()           Update Autoincrement Counters from the last row inserted.
void	validateStatement(org.apache.derby.iapi.sql.execute.ConstantAction constantAction)           Make sure that whatever statement is about to be executed is ok from the context of this trigger.
boolean	wasColumnModified(int columnNumber)           Find out of a column was changed, by column number
boolean	wasColumnModified(java.lang.String columnName)           Find out of a column was changed, by column name

 

Methods inherited from class java.lang.Object

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

 

Field Detail

changedColIds

protected int[] changedColIds

---

changedColNames

protected java.lang.String[] changedColNames

---

dmlType

protected int dmlType

---

statementText

protected java.lang.String statementText

---

cc

protected org.apache.derby.iapi.jdbc.ConnectionContext cc

---

targetTableId

protected org.apache.derby.catalog.UUID targetTableId

---

targetTableName

protected java.lang.String targetTableName

---

lcc

protected org.apache.derby.iapi.sql.conn.LanguageConnectionContext lcc

---

beforeResultSet

protected org.apache.derby.iapi.sql.execute.CursorResultSet beforeResultSet

---

afterResultSet

protected org.apache.derby.iapi.sql.execute.CursorResultSet afterResultSet

---

afterRow

protected org.apache.derby.iapi.sql.execute.ExecRow afterRow

used exclusively for InsertResultSets which have autoincrement columns.

---

cleanupCalled

protected boolean cleanupCalled

---

event

protected TriggerEvent event

---

triggerd

protected org.apache.derby.iapi.sql.dictionary.TriggerDescriptor triggerd

---

resultSetVector

private java.util.Vector resultSetVector

---

aiCounters

private java.util.Vector aiCounters

aiCounters is a vector of AutoincrementCounters used to keep state which might be used by the trigger. This is only used by Insert triggers-- Delete and Update triggers do not use this variable.

See Also:

AutoincrementCounter

---

aiHT

private java.util.Hashtable aiHT

aiHT is a hashtable of autincrement pairs. This is used for ai values generated by the trigger.

Constructor Detail

InternalTriggerExecutionContext

public InternalTriggerExecutionContext(org.apache.derby.iapi.sql.conn.LanguageConnectionContext lcc,
                                       org.apache.derby.iapi.jdbc.ConnectionContext cc,
                                       java.lang.String statementText,
                                       int dmlType,
                                       int[] changedColIds,
                                       java.lang.String[] changedColNames,
                                       org.apache.derby.catalog.UUID targetTableId,
                                       java.lang.String targetTableName,
                                       java.util.Vector aiCounters)
                                throws org.apache.derby.iapi.error.StandardException

Build me a big old nasty trigger execution context. Damnit.

About the only thing of real interest to outside observers is that it pushes itself as the trigger execution context in the lcc. Be sure to call cleanup() when you are done, or you will be flogged like the reprobate that you are.

Method Detail

setBeforeResultSet

void setBeforeResultSet(org.apache.derby.iapi.sql.execute.CursorResultSet rs)

---

setAfterResultSet

void setAfterResultSet(org.apache.derby.iapi.sql.execute.CursorResultSet rs)
                 throws org.apache.derby.iapi.error.StandardException

---

setCurrentTriggerEvent

void setCurrentTriggerEvent(TriggerEvent event)

---

clearCurrentTriggerEvent

void clearCurrentTriggerEvent()

---

setTrigger

void setTrigger(org.apache.derby.iapi.sql.dictionary.TriggerDescriptor triggerd)

---

clearTrigger

void clearTrigger()
            throws org.apache.derby.iapi.error.StandardException

---

cleanup

protected void cleanup()
                throws org.apache.derby.iapi.error.StandardException

Cleanup the trigger execution context. MUST be called when the caller is done with the trigger execution context.

We go to somewhat exaggerated lengths to free up all our resources here because a user may hold on to a TEC after it is valid, so we clean everything up to be on the safe side.

---

ensureProperContext

private void ensureProperContext()
                          throws java.sql.SQLException

Make sure that the user isn't trying to get a result set after we have cleaned up.

---

validateStatement

public void validateStatement(org.apache.derby.iapi.sql.execute.ConstantAction constantAction)
                       throws org.apache.derby.iapi.error.StandardException

Make sure that whatever statement is about to be executed is ok from the context of this trigger.

Note that we are sub classed in replication for checks for replication specific language.

Specified by:

validateStatement in interface org.apache.derby.iapi.sql.execute.ExecutionStmtValidator

---

getTargetTableName

public java.lang.String getTargetTableName()

Get the target table name upon which the trigger event is declared.

Specified by:

getTargetTableName in interface org.apache.derby.iapi.db.TriggerExecutionContext

---

getTargetTableId

public org.apache.derby.catalog.UUID getTargetTableId()

Get the target table UUID upon which the trigger event is declared.

Specified by:

getTargetTableId in interface org.apache.derby.iapi.db.TriggerExecutionContext

---

getEventType

public int getEventType()

Get the type for the event that caused the trigger to fire.

Specified by:

getEventType in interface org.apache.derby.iapi.db.TriggerExecutionContext

---

getEventStatementText

public java.lang.String getEventStatementText()

Get the text of the statement that caused the trigger to fire.

Specified by:

getEventStatementText in interface org.apache.derby.iapi.db.TriggerExecutionContext

---

getModifiedColumns

public java.lang.String[] getModifiedColumns()

Get the columns that have been modified by the statement that caused this trigger to fire. If all columns are modified, will return null (e.g. for INSERT or DELETE will return null).

Specified by:

getModifiedColumns in interface org.apache.derby.iapi.db.TriggerExecutionContext

---

wasColumnModified

public boolean wasColumnModified(java.lang.String columnName)

Find out of a column was changed, by column name

Specified by:

wasColumnModified in interface org.apache.derby.iapi.db.TriggerExecutionContext

---

wasColumnModified

public boolean wasColumnModified(int columnNumber)

Find out of a column was changed, by column number

Specified by:

wasColumnModified in interface org.apache.derby.iapi.db.TriggerExecutionContext

---

getOldRowSet

public java.sql.ResultSet getOldRowSet()
                                throws java.sql.SQLException

Returns a result set row the old images of the changed rows. For a row trigger, the result set will have a single row. For a statement trigger, this result set has every row that has changed or will change. If a statement trigger does not affect a row, then the result set will be empty (i.e. ResultSet.next() will return false).

Specified by:

getOldRowSet in interface org.apache.derby.iapi.db.TriggerExecutionContext

---

getNewRowSet

public java.sql.ResultSet getNewRowSet()
                                throws java.sql.SQLException

Returns a result set row the new images of the changed rows. For a row trigger, the result set will have a single row. For a statement trigger, this result set has every row that has changed or will change. If a statement trigger does not affect a row, then the result set will be empty (i.e. ResultSet.next() will return false).

Specified by:

getNewRowSet in interface org.apache.derby.iapi.db.TriggerExecutionContext

---

getOldRow

public java.sql.ResultSet getOldRow()
                             throws java.sql.SQLException

Like getBeforeResultSet(), but returns a result set positioned on the first row of the before result set. Used as a convenience to get a column for a row trigger. Equivalent to getBeforeResultSet() followed by next().

Specified by:

getOldRow in interface org.apache.derby.iapi.db.TriggerExecutionContext

---

getNewRow

public java.sql.ResultSet getNewRow()
                             throws java.sql.SQLException

Like getAfterResultSet(), but returns a result set positioned on the first row of the before result set. Used as a convenience to get a column for a row trigger. Equivalent to getAfterResultSet() followed by next().

Specified by:

getNewRow in interface org.apache.derby.iapi.db.TriggerExecutionContext

---

getAutoincrementValue

public java.lang.Long getAutoincrementValue(java.lang.String identity)

---

copyHashtableToAIHT

public void copyHashtableToAIHT(java.util.Hashtable from)

Copy a hashtable of autoincrement values into the trigger execution context hashtable of autoincrement values.

---

resetAICounters

public void resetAICounters(boolean begin)

Reset Autoincrement counters to the beginning or the end.

---

updateAICounters

public void updateAICounters()
                      throws org.apache.derby.iapi.error.StandardException

Update Autoincrement Counters from the last row inserted.

---

toString

public java.lang.String toString()

Description copied from class: java.lang.Object

Convert this Object to a human-readable String. There are no limits placed on how long this String should be or what it should contain. We suggest you make it as intuitive as possible to be able to place it into System.out.println() 55 and such.

It is typical, but not required, to ensure that this method never completes abruptly with a java.lang.RuntimeException.

This method will be called when performing string concatenation with this object. If the result is null, string concatenation will instead use "null".

The default implementation returns getClass().getName() + "@" + Integer.toHexString(hashCode()).

---

Overview  Package   Class  Use  Deprecated  Index
Home >> All >> org >> apache >> derby >> impl >> sql >> [ execute overview ]	PREV CLASS  NEXT CLASS
SUMMARY:  JAVADOC |  SOURCE |  DOWNLOAD | NESTED | FIELD | CONSTR | METHOD	DETAIL: FIELD | CONSTR | METHOD

---