create table DEPT_INFO(DEPT_NAME char(3),AUTH int)

insert DEPT_INFO

select 'AAA',1 union all

select 'AAA',1 union all

select 'AAA',2 union all

select 'AAA',1 union all

select 'BBB',3 union all

select 'BBB',3 union all

select 'CCC',1 union all

select 'CCC',2 union all

select 'CCC',3

------------------------------------

select DEPT_NAME,count(distinct AUTH) AUTH_COUNT from DEPT_INFO group by DEPT_NAME

/*

DEPT_NAME AUTH_COUNT

--------- -----------

AAA       2

BBB       1

CCC       3

(3개 행 적용됨)

*/

감사합니다^^
이런 방법도있었다는거...

잘 배우고 가요..

감사합니다^^