Other columns with group by

Question

Hi,
Using oracle 10g on windows:
I want to get all the columns of scott.emp table group by deptno.
Because if i gives :
select * from emp group by detpno; then its gives me ORA-00979: not a GROUP BY expression
In addition to this please tell me how do i get if i wish to group by deptno,job.
Thanks in advance.

Answer 1

Yes, because i just want to get all the columns of any row of every dept numberGetting all rows doesn't mean you'll need a GROUP BY.
You'll need a GROUP BY when you want to aggregate values.
just want to fetch a single/any row group by deptno.I still think you want to use ORDER BY then:
SQL> -- 1. incorrect query
SQL> -- you cannot select * and use a group by
SQL> select *
  2  from   hr.employees e
  3  where rownum <= 10
  4  group by e.department_id
  5  ,        e.first_name;
select *
ERROR at line 1:
ORA-00979: not a GROUP BY expression
SQL>
SQL> --2. this doesn't order or group anything
SQL> select e.department_id 
  2  ,      e.first_name
  3  from   hr.employees e
  4  where rownum <= 10
  5  group by e.department_id
  6  ,        e.first_name;
DEPARTMENT_ID FIRST_NAME
           90 Steven
           60 Diana
           60 Alexander
           90 Lex
           60 Bruce
           60 Valli
          100 Nancy
           60 David
           90 Neena
          100 Daniel
10 rows selected.
SQL>
SQL> --3. using order by any column you want
SQL> --(here you can use select * as well, by the way)
SQL> select e.department_id 
  2  ,      e.first_name
  3  from   hr.employees e
  4  where rownum <= 10
  5  order by e.department_id
  6  ,        e.first_name;
DEPARTMENT_ID FIRST_NAME
           60 Alexander
           60 Bruce
           60 David
           60 Diana
           60 Valli
           90 Lex
           90 Neena
           90 Steven
          100 Daniel
          100 Nancy
10 rows selected.
SQL> [Group by|http://download.oracle.com/docs/cd/B19306_01/server.102/b14200/statements_10002.htm#i2182483]
[Order by|http://download.oracle.com/docs/cd/B19306_01/server.102/b14200/statements_10002.htm#i2171079]