How to create MIN/MAX limitations in SELECT statement ??

Question

Hey,
I have a table which rank90 (city population ranked from 1>*) and state_abrv which has the corresponding state for each city rank.
Is there a way to select only the maximum AND minimum ranks for each state ??
I realise there is a max and min function, but i need to do it for EACH state_abrv.
An example say Los Angeles is ranked 2, San Diego is ranked 6, and San Fransico is ranked 14 (All of these citys are in california (CA)). How do i display a table which lists only Los Angeles (Highest rank) and San Fransico (lowest rank) but DOESNT list San diego ??
Thanks, you guys are helping me heaps and im starting to learn a lot more :P
Message was edited by:
user495524

Answer 1

SQL> create table t (state varchar2(2), city varchar2(20), n number);
Table created.
SQL> insert into t values ('CA','San Francisco',14);
1 row created.
SQL> insert into t values ('CA','San Diego',6);
1 row created.
SQL> insert into t values ('CA','Los Angeles',2);
1 row created.
SQL> insert into t values ('NY','Buffalo',4);
1 row created.
SQL> insert into t values ('NY','Syracuse',7);
1 row created.
SQL> insert into t values ('NY','Mt Kisco',2);
1 row created.
SQL> insert into t values ('NY','Albany',5);
1 row created.
SQL> select * from t order by state, n desc;
ST CITY                          N
CA San Francisco                14
CA San Diego                     6
CA Los Angeles                   2
NY Syracuse                      7
NY Albany                        5
NY Buffalo                       4
NY Mt Kisco                      2
7 rows selected.
SQL> select state, city, n from
  2    (
  3    select t.*, min(n) over (partition by state) min_n,
  4      max(n) over (partition by state) max_n from t
  5    )
  6  where n in (min_n, max_n) order by state, n desc;
ST CITY                          N
CA San Francisco                14
CA Los Angeles                   2
NY Syracuse                      7
NY Mt Kisco                      2
SQL>