Trigger
A class that implements this interface can be used as a trigger.
Methods |
void |
close()
This method is called when the database is closed.
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void |
close() throws SQLException
This method is called when the database is closed.
If the method throws an exception, it will be logged, but
closing the database will continue.
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void |
fire(Connection conn, Object[] oldRow, Object[] newRow)
This method is called for each triggered action.
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void |
fire(Connection conn, Object[] oldRow, Object[] newRow) throws SQLException
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.
Parameters:
conn - a connection to the database
oldRow - the old row, or null if no old row is available (for
INSERT)
newRow - the new row, or null if no new row is available (for
DELETE)
Throws:
SQLException - if the operation must be undone
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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.
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void |
init(Connection conn, String schemaName, String triggerName, String tableName, boolean before, int type) throws SQLException
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).
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)
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void |
remove()
This method is called when the trigger is dropped.
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void |
remove() throws SQLException
This method is called when the trigger is dropped.
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INSERT
= 1
The trigger is called for INSERT statements.
UPDATE
= 2
The trigger is called for UPDATE statements.
DELETE
= 4
The trigger is called for DELETE statements.
SELECT
= 8
The trigger is called for SELECT statements.
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