How to use the etlhelper.db_params.DbParams.from_environment function in etlhelper

def test_db_params_from_environment_not_set(monkeypatch):
    """
    Test missing db params from environment settings.
    """
    # Arrange
    monkeypatch.delenv('TEST_DBTYPE', raising=False)

    # Act
    with pytest.raises(ETLHelperDbParamsError,
                       match=r".*environment variable is not set.*"):
        DbParams.from_environment(prefix='TEST_')

def test_db_params_from_environment(monkeypatch):
    """
    Test capturing db params from environment settings.
    """
    # Arrange
    monkeypatch.setenv('TEST_DB_PARAMS_ENV_DBTYPE', 'ORACLE')
    monkeypatch.setenv('TEST_DB_PARAMS_ENV_HOST', 'test.host')
    monkeypatch.setenv('TEST_DB_PARAMS_ENV_PORT', '1234')
    monkeypatch.setenv('TEST_DB_PARAMS_ENV_DBNAME', 'testdb')
    monkeypatch.setenv('TEST_DB_PARAMS_ENV_USER', 'testuser')

    # Act
    db_params = DbParams.from_environment(prefix='TEST_DB_PARAMS_ENV_')

    # Assert
    db_params.dbtype = 'ORACLE'
    db_params.host = 'test.host'
    db_params.port = '1234'
    db_params.dbname = 'testdb'
    db_params.user = 'testuser'