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package org.hsqldb.trigger;
import org.hsqldb.HsqlException;
// fredt@users 20030727 - signature altered to support update triggers
// fredt@users 20190327 - moved to own package
/*
Contents of row1[] and row2[] in each type of trigger.
AFTER INSERT
- row1[] contains single String object = "Statement-level".
AFTER UPDATE
- row1[] contains single String object = "Statement-level".
AFTER DELETE
- row1[] contains single String object = "Statement-level".
BEFORE INSERT FOR EACH ROW
- row2[] contains data about to be inserted and this can
be modified within the trigger such that modified data gets written to the
database.
AFTER INSERT FOR EACH ROW
- row2[] contains data just inserted into the table.
BEFORE UPDATE FOR EACH ROW
- row1[] contains currently stored data and not the data that is about to be
updated.
- row2[] contains the data that is about to be updated.
AFTER UPDATE FOR EACH ROW
- row1[] contains old stored data.
- row2[] contains the new data.
BEFORE DELETE FOR EACH ROW
- row1[] contains row data about to be deleted.
AFTER DELETE FOR EACH ROW
- row1[] contains row data that has been deleted.
List compiled by Andrew Knight (quozzbat@users)
*/
/**
* The interface an HSQLDB TRIGGER must implement. The user-supplied class that
* implements this must have a default constructor.
*
* @author Peter Hudson (peterhudson@users dot sourceforge.net)
* @version 1.9.0
* @since 1.7.0
*/
public interface Trigger {
// type of trigger
int INSERT_AFTER = 0;
int DELETE_AFTER = 1;
int UPDATE_AFTER = 2;
int INSERT_AFTER_ROW = 3;
int DELETE_AFTER_ROW = 4;
int UPDATE_AFTER_ROW = 5;
int INSERT_BEFORE_ROW = 6;
int DELETE_BEFORE_ROW = 7;
int UPDATE_BEFORE_ROW = 8;
/**
* The method invoked upon each triggered action.
*
* type contains the integer index id for trigger type, e.g.
* TriggerDef.INSERT_AFTER
*
*
For all triggers defined as default FOR EACH STATEMENT both
* oldRow and newRow are null.
*
*
For triggers defined as FOR EACH ROW, the following will apply:
*
*
When UPDATE triggers are fired, oldRow contains the existing values
* of the table row and newRow contains the new values.
*
*
For INSERT triggers, oldRow is null and newRow contains the table row
* to be inserted. For DELETE triggers, newRow is null and oldRow contains
* the table row to be deleted.
*
*
For error conditions, users can construct an HsqlException using one
* of the static methods of org.hsqldb.error.Error with a predefined
* SQL State from org.hsqldb.error.ErrorCode.
*
* @param type the type as one of the int values defined in the interface
* @param trigName the name of the trigger
* @param tabName the name of the table upon which the triggered action is
* occurring
* @param oldRow the old row
* @param newRow the new row
* @throws HsqlException the preferred type of exception thrown by the method
*/
void fire(int type, String trigName, String tabName, Object[] oldRow,
Object[] newRow);
}