def join_query_string(qs_dict):
    """
    Joins query string from a dictionary
    
    >>> join_query_string({'a': '1', 'y': '', 'b': '2', 'name': 'abc', 'z': 'ab23'})
    'a=1&y=&b=2&name=abc&z=ab23'
    """
    parts = []
    for k, v in qs_dict.items():
        parts.append('{}={}'.format(k, v))
    return '&'.join(parts)
