j = alert.join(address_src,
                   and_(address_src.c._parent_type == 'S',
                        address_src.c._message_ident == alert.c._ident,
                        address_src.c._index == 0,
                        address_src.c._parent0_index == 0))
    j = j.join(address_dst,
               and_(address_dst.c._parent_type == 'T',
                    address_dst.c._message_ident == alert.c._ident,
                    address_dst.c._index == 0,
                    address_dst.c._parent0_index == 0))
    j = j.join(create_time,
               and_(create_time.c._message_ident == alert.c._ident,
	            create_time.c._parent_type == 'A'))
    j = j.join(classification, classification.c._message_ident == alert.c._ident)
    j = j.join(impact, impact.c._message_ident == alert.c._ident)