資料庫Oracle之多表查詢:笛卡爾積、等值連線、不等值連線、外連線,自連線
阿新 • • 發佈:2019-01-30
select e.empno, e.ename, e.sal, s.grade
from emp e, SALGRADE s
where e.sal >= s.losal and e.sal <= s.hisal
-- where e.sal between s.losal and s.hisal
EMPNOENAME SAL GRADE
---------- ---------- ---------- ----------
7369 SMITH 800 1
7900JAMES 950 1
7876ADAMS 1100 1
7521WARD 1250 2
7654MARTIN 1250 2
7934MILLER 1300 2
7844TURNER 1500 3
7499ALLEN 1600 3
7782CLARK 2450 4
7698BLAKE 2850 4
7566JONES 2975 4
7788 SCOTT 3000 4
7902FORD 3000 4
7839KING 5000 5