sql example
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> select * from tab; // 테이블 명을 보여준다
TNAME TABTYPE CLUSTERID
------------------------------------------- -------------- ----------
EMP TABLE
DEPT TABLE
BONUS TABLE
SALGRADE TABLE
DUMMY TABLE
> desc emp
이름 널? 유형
-------------------------------------------- -------- -------------------
EMPNO NOT NULL NUMBER(4)
ENAME VARCHAR2(10)
JOB VARCHAR2(9)
MGR NUMBER(4)
HIREDATE DATE
SAL NUMBER(7,2)
COMM NUMBER(7,2)
DEPTNO NUMBER(2)
// alias를 사용한다. " "로 묶으면 묶은 그대로 나오고 아니면 무조건 대문자로 나온다
> select job as "abc" from emp;
abc
------------------
CLERK
SALESMAN
SALESMAN
MANAGER
SALESMAN
MANAGER
MANAGER
ANALYST
PRESIDENT
SALESMAN
CLERK
abc
------------------
CLERK
ANALYST
CLERK
> select job as abc from emp;
ABC
------------------
CLERK
SALESMAN
SALESMAN
MANAGER
SALESMAN
MANAGER
MANAGER
ANALYST
PRESIDENT
SALESMAN
CLERK
ABC
------------------
CLERK
ANALYST
CLERK
> select * from emp
order by deptno asc, sal desc;
EMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO
----- ------------ ------------- ----- -------- ----- ------- -------
7839 KING PRESIDENT 81/11/17 5000 10
7782 CLARK MANAGER 7839 81/06/09 2450 10
7934 MILLER CLERK 7782 82/01/23 1300 10
7788 SCOTT ANALYST 7566 82/12/09 3000 20
7902 FORD ANALYST 7566 81/12/03 3000 20
7566 JONES MANAGER 7839 81/04/02 2975 20
7876 ADAMS CLERK 7788 83/01/12 1100 20
7369 SMITH CLERK 7902 80/12/17 800 20
7698 BLAKE MANAGER 7839 81/05/01 2850 30
7499 ALLEN SALESMAN 7698 81/02/20 1600 300 30
7844 TURNER SALESMAN 7698 81/09/08 1500 0 30
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