SQL-기초(2) 집합연산자
emp 테이블에서 부서 번호 10,20 인 사원번호, 이름, 급여 , 부서번호 합집합select empno, ename, deptno from emp where deptno = 10UNIONselect empno, ename, deptno from emp where deptno = 20; select empno, ename, sal, deptno from empunionselect empno, ename, sal, deptno from emp where deptno =20;차집합select empno, ename, sal, deptno from empMINUSselect empno, ename, sal, deptno from emp where deptno =20;교집합select empno, ename,..
2024. 6. 7.