Create

Here are the tests for Sql2oCourseDao.create method:

@Test
@DisplayName("create works for valid input")
void createNewCourse() {
  Course c1 = new Course("EN.601.421", "Object-Oriented Software Engineering");
  Course c2 = courseDao.create(c1.getOfferingName(), c1.getTitle());
  assertEquals(c1, c2);
}

@Test
@DisplayName("create throws exception for duplicate course")
void createThrowsExceptionDuplicateData() {
  assertThrows(DaoException.class, () -> {
    courseDao.create("EN.500.112", "GATEWAY COMPUTING: JAVA");
  });
}

@Test
@DisplayName("create throws exception for invalid input")
void createThrowsExceptionIncompleteData() {
  assertThrows(DaoException.class, () -> {
    courseDao.create(null, null);
  });
}

And here is the implementation of Sql2oCourseDao.create:

@Override
public Course create(String offeringName, String title) throws DaoException {
  String sql = "WITH inserted AS ("
      + "INSERT INTO courses(offeringName, title) VALUES(:name, :title) RETURNING *"
      + ") SELECT * FROM inserted;";
  try (Connection conn = sql2o.open()) {
    return conn.createQuery(sql)
        .addParameter("name", offeringName)
        .addParameter("title", title)
        .executeAndFetchFirst(Course.class);
  } catch (Sql2oException ex) {
    throw new DaoException(ex.getMessage(), ex);
  }
}

Run the tests and make sure they pass!