DB Wiki

Create a period using existing columns

CREATE TABLE student_modules (
  id         NUMBER(10) NOT NULL,
  student_id NUMBER(10) NOT NULL,
  module_id  NUMBER(10) NOT NULL,
  start_date DATE,
  end_date   DATE,
  PERIOD FOR student_module_period (start_date, end_date)
);

Create a period with system generated hidden columns

CREATE TABLE student_modules (
  id         NUMBER(10) NOT NULL,
  student_id NUMBER(10) NOT NULL,
  module_id  NUMBER(10) NOT NULL,
  start_date DATE,
  end_date   DATE,
  PERIOD FOR student_module_period
  );

We can now create AS OF PERIOD FOR queries

SELECT * FROM student_modules AS OF 
                 PERIOD FOR student_module_period TO_DATE('12-FEB-2013','DD-MON-YYYY') sm;