Describe 首頁/2020-11-22 here.
* OCP Day2
Operator
SQL> select distinct job from emp where deptno=20; JOB ------------------ CLERK ANALYST MANAGER 1 select distinct job from emp where deptno=20 2 UNION 3* select distinct job from emp where deptno=30 SQL> / JOB ------------------ ANALYST CLERK MANAGER SALESMAN 1 select distinct job from emp where deptno=20 2 UNION all 3* select distinct job from emp where deptno=30 SQL> / JOB ------------------ CLERK ANALYST MANAGER SALESMAN CLERK MANAGER 6 rows selected.
1 select distinct job from emp where deptno=20 2 minus 3* select distinct job from emp where deptno=30 SQL> / JOB ------------------ ANALYST