def stringify(data):
    """Sanitize collection data into a string format for db storage.

    Args:
        data (str, bool, numeric, dict, list): Values to
            squash into strings.

    Returns:
        list data returns as a comma separated string or '{EMPTY}'
        if the list is empty.

        All other data types are `str()` converted, including nested
        collections in a list.
    """
    if isinstance(data, list):
        return ", ".join(str(i) for i in data) if data else "{EMPTY}"

    # Handle dict, int, float, bool values.
    return str(data)