제5장 다표는 교실 노트와 연습을 연결한다
3557 단어 Oracle 데이터베이스 학습 노트
,
,
-oracle 자체 쓰기: 등치 연결, 비등치 연결, 외부 연결, 자체 연결
select * from emp,dept;-- :emp *dept
select emp.*,dept.*
from emp,dept
where emp.deptno = dept.deptno;
select empno,ename,dept.deptno,loc
from emp,dept
where emp.deptno = dept.deptno;
-- ,
--
;
;
;
---- and
select empno,ename,dept.deptno,loc
from emp,dept
where emp.deptno = dept.deptno and loc = 'NEW YORK';
select e.ename, e.sal, s.grade
from emp e,salgrade s
where e.sal between s.losal and s.hisal;
1. , FROM ;
2. ,
, , FROM
;
3. WHERE , N
, N-1 ;
4. , WHERE
, ;
5. , SELECT 。
6. ,
, 2 ,
;
-- , , ,
SELECT e.ename, d.deptno, d.dname
FROM emp e, dept d
WHERE e.deptno(+) = d.deptno
ORDER BY e.deptno;
-- , , ,
SELECT e.ename, d.deptno, d.dname
FROM emp e, dept d
WHERE e.deptno = d.deptno(+)
ORDER BY e.deptno;
--
select e.ename,
mgr.ename
from emp e,emp mgr
where e.mgr = mgr.empno;
- SQL:1999 구문의 연결 select * from emp cross join dept;
select * from emp natural join dept;
select * from emp join dept using(deptno);
select * from emp join dept on(emp.deptno = dept.deptno);
select * from emp
left outer join dept on(emp.deptno = dept.deptno);
select * from emp
right outer join dept on(emp.deptno = dept.deptno);
select * from emp
full outer join dept on(emp.deptno = dept.deptno);