

## 1 ~ N 까지의 숫자 구하기
SELECT LEVEL AS num 
FROM dual 
CONNECT BY LEVEL <= 3


## 테이블 스페이스 보기
SQL>select name from v$tablespace; 

## 사용자 별 테이블 스페이스
select USERNAME,DEFAULT_TABLESPACE,TEMPORARY_TABLESPACE
from dba_users;


#### SQL 문장을 조사 
프로그램을 일일이 뒤지기 보다는 SHARD POOL 에 있는 SQL문을 구한다.

ALTER SYSTEM FLUSH SHARED_POOL;
select * from scott.emp;
select * from scott.emp where rownum <= 1

select a.*
from  v$sqltext a,v$sql c
where a.hash_value=c.hash_value
    and a.address=c.address
    and PARSING_USER_ID <> '0'
    and a.COMMAND_TYPE = 3
    order by a.HASH_VALUE,a.piece;


#### 데이터를 램덤하게 Select 

select * from table_name sample(5) where rownum<11;

(5) : 5% sample 추출을 의미합니다.


select *
from (
	select *
	from table
	where date '20070101' and '20070601'
	order by dbms_random.random
)
where rownum <= 10


###################################################
CONNECT BY PRIOR TARGET_CD = BASE_CD
START WITH BASE_CD = '*'


SELECT A.제품번호
	 , A.기타등등 정보
	 , B.결함코드
	 , RANK() OVER(PARTITION BY A.제품번호, A.공정
			   ORDER BY B.재처리횟수 DESC) rk
FROM 테이블 1 A
   , 테이블 2 B


##
with master
as (
    select 'M001' code, '성별' content from dual
    union all select 'M002' code, '연령' content from dual 
    union all select 'M004' code, '지역' content from dual
   ), detail
as (
    select 'M001' code, '01' seq, '남자' dcontent from dual 
    union all select 'M001' code, '02' seq, '여자' dcontent from dual 
    union all select 'M002' code, '01' seq, '10대' dcontent from dual 
    union all select 'M002' code, '02' seq, '20대' dcontent from dual  
   )

select  구문...
from master x, detail y, ..