[Oracle SQL] SELECT 실습_ WHERE 절; 연산

[Oracle SQL] SELECT 실습_ WHERE 절

I WHERE

▶ WHERE : 원하는 ROW만 조회

1. 

SELECT * FROM EMP WHERE DEPTNO = 20;

2.

SELECT EMPNO, ENAME, JOB, SAL FROM EMP WHERE SAL > 1500;

3. 

SELECT EMPNO, ENAME, JOB, SAL, DEPTNO FROM EMP WHERE DEPTNO = 20 AND SAL > 1500;

4. 

SELECT DEPTNO, ENAME, JOB FROM EMP WHERE JOB = 'SALESMAN';

5.

SELECT DEPTNO, ENAME, JOB FROM EMP WHERE 1=1;

6.

SELECT DEPTNO, ENAME, JOB FROM EMP WHERE 1=2;

I 비교연산, 사칙연산

1. 

SELECT EMPNO, ENAME, SAL, SAL*12, COMM, COMM+300 FROM EMP;

2. 연산자 우선순위 확인

SELECT EMPNO, ENAME, SAL, SAL+500*12,(SAL+500)*12 FROM EMP;