How do you select distinct rows that are similar but not identical

From: colinlyse <colinlyse_at_yahoo.com>
Date: 3 Dec 2003 08:25:34 -0600
Message-ID: <3fcdf1d3$0$214$45beb828@newscene.com>

have a resultset as follows (its result of of a connect by, prior tree query that shows me the hier. of substations) it is ordered by the Level desc.

LEVEL     TERMINAL_ID_SQ  SUBSTATION              TERMINAL_NAME
10              11664                   TAS50                           69KV1
8               11664                    TAS50                          69KV1
6               7782                      TSR41                         1
4               7782                      TSR41                         1
2               7500                      DC315                        4kV-1

I want the following result set

SUBSTATION              TERMINAL_NAME
TAS50                         69KV1
TSR41                         1
DC315                        4kV-1

note that is has to be in the order of the level but i don't want to see same instance of substation eventhought it is at a different level (don't care it it uses level 10 or 8 they are identical in station and terminal names) Received on Wed Dec 03 2003 - 08:25:34 CST