Update

Here are the tests for Sql2oCourseDao.update method:

@Test
@DisplayName("updating a course works")
void updateWorks() {
  String title = "Updated Title!";
  Course course = courseDao.update(samples.get(0).getOfferingName(), title);
  assertEquals(title, course.getTitle());
  assertEquals(samples.get(0).getOfferingName(), course.getOfferingName());
}

@Test
@DisplayName("Update returns null for an invalid offeringCode")
void updateReturnsNullInvalidCode() {
  Course course = courseDao.update("EN.000.999", "UpdatedTitle");
  assertNull(course);
}

@Test
@DisplayName("Update throws exception for an invalid title")
void updateThrowsExceptionInvalidTitle() {
  assertThrows(DaoException.class, () -> {
    courseDao.update(samples.get(0).getOfferingName(), null);
  });
}

And here is the implementation of Sql2oCourseDao.update:

@Override
public Course update(String offeringName, String title) throws DaoException {
  String sql = "WITH updated AS ("
      + "UPDATE courses SET title = :title WHERE offeringName = :name RETURNING *"
      + ") SELECT * FROM updated;";
  try (Connection conn = sql2o.open()) {
    return conn.createQuery(sql)
        .addParameter("title", title)
        .addParameter("name", offeringName)
        .executeAndFetchFirst(Course.class);
  } catch (Sql2oException ex) {
    throw new DaoException("Unable to update the course", ex);
  }
}

Run the tests and make sure they pass!