Examples Of

Examples of `CREATE TRIGGER` for “Database Triggers”

Creating a trigger for the event of connecting to the database that logs users logging into the system.The trigger is created as inactive.

CREATE TRIGGER tr_log_connect
INACTIVE ON CONNECT POSITION 0
AS
BEGIN
  INSERT INTO LOG_CONNECT (ID,
                           USERNAME,
                           ATIME)
  VALUES (NEXT VALUE FOR SEQ_LOG_CONNECT,
          CURRENT_USER,
          CURRENT_TIMESTAMP);
END

Creating a trigger for the event of connecting to the database that does not permit any users, except for SYSDBA, to log in during off hours.

CREATE EXCEPTION E_INCORRECT_WORKTIME 'The working day has not started yet.';

CREATE TRIGGER TR_LIMIT_WORKTIME ACTIVE
ON CONNECT POSITION 1
AS
BEGIN
  IF ((CURRENT_USER <> 'SYSDBA') AND
      NOT (CURRENT_TIME BETWEEN time '9:00' AND time '17:00')) THEN
    EXCEPTION E_INCORRECT_WORKTIME;
END

DDL Triggers

DDL triggers allow restrictions to be placed on users who attempt to create, alter or drop a DDL object.Their other purposes is to keep a metadata change log.

DDL triggers fire on specified metadata changes events in a specified phase.BEFORE triggers run before changes to system tables.AFTER triggers run after changes in system tables.

Important

The event type [BEFORE | AFTER] of a DDL trigger cannot be changed.

In a sense, DDL triggers are a sub-type of database triggers.

Examples Of

Examples of CREATE TRIGGER for “Database Triggers”

DDL Triggers

Examples of `CREATE TRIGGER` for “Database Triggers”