Package org.h2.samples

Class TriggerPassData

java.lang.Object

org.h2.samples.TriggerPassData

All Implemented Interfaces:

Trigger

public class TriggerPassData
extends Object
implements Trigger

This sample application shows how to pass data to a trigger. Trigger data can be persisted by storing it in the database.

Field Summary

Fields inherited from interface org.h2.api.Trigger

DELETE, INSERT, SELECT, UPDATE

Constructor Summary

Constructors

Constructor	Description
TriggerPassData()

Method Summary

Modifier and Type	Method	Description
void	fire(Connection conn, Object[] old, Object[] row)	This method is called for each triggered action.
void	init(Connection conn, String schemaName, String triggerName, String tableName, boolean before, int type)	This method is called by the database engine once when initializing the trigger.
static void	main(String... args)	This method is called when executing this sample application from the command line.
static void	setTriggerData(Connection conn, String trigger, String data)	Call this method to change a specific trigger.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.h2.api.Trigger

close, remove

Constructor Details

TriggerPassData

public TriggerPassData()

Method Details

main

public static void main(String... args)
                 throws Exception

This method is called when executing this sample application from the command line.

Parameters:

args - the command line parameters

Throws:

Exception - on failure

init

public void init(Connection conn,
 String schemaName,
 String triggerName,
 String tableName,
 boolean before,
 int type)
          throws SQLException

Description copied from interface: Trigger

This method is called by the database engine once when initializing the trigger. It is called when the trigger is created, as well as when the database is opened. The type of operation is a bit field with the appropriate flags set. As an example, if the trigger is of type INSERT and UPDATE, then the parameter type is set to (INSERT | UPDATE).

Specified by:

init in interface Trigger

Parameters:

conn - a connection to the database (a system connection)

schemaName - the name of the schema

triggerName - the name of the trigger used in the CREATE TRIGGER statement

tableName - the name of the table

before - whether the fire method is called before or after the operation is performed

type - the operation type: INSERT, UPDATE, DELETE, SELECT, or a combination (this parameter is a bit field)

Throws:

SQLException - on SQL exception

fire

public void fire(Connection conn,
 Object[] old,
 Object[] row)

Description copied from interface: Trigger

This method is called for each triggered action. The method is called immediately when the operation occurred (before it is committed). A transaction rollback will also rollback the operations that were done within the trigger, if the operations occurred within the same database. If the trigger changes state outside the database, a rollback trigger should be used.

The row arrays contain all columns of the table, in the same order as defined in the table.

The trigger itself may change the data in the newRow array.

Specified by:

fire in interface Trigger

Parameters:

conn - a connection to the database

old - the old row, or null if no old row is available (for INSERT)

row - the new row, or null if no new row is available (for DELETE)

setTriggerData

public static void setTriggerData(Connection conn,
 String trigger,
 String data)
                           throws SQLException

Call this method to change a specific trigger.

Parameters:

conn - the connection

trigger - the trigger name

data - the data

Throws:

SQLException - on failure