[Oracle SQL] SELECT 실습_ 논리연산자

[Oracle SQL] SELECT 실습_ 논리연산자

I 논리연산자 (AND, OR, NOT)

▶ 연산자 우선순위 : AND > OR

1. AND, OR 비교

1) AND

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SELECT DEPTNO,ENAME,JOB,SAL FROM EMP WHERE DEPTNO=20 AND SAL>2500;

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2) OR

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SELECT DEPTNO,ENAME,JOB,SAL FROM EMP WHERE DEPTNO=20 OR SAL>2500;

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2. 연산자 우선순위

1) AND ~ OR

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SELECT DEPTNO,ENAME,JOB,SAL FROM EMP WHERE DEPTNO=20 AND SAL>2500 OR JOB='CLERK';

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2) OR ~ AND

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SELECT DEPTNO,ENAME,JOB,SAL FROM EMP WHERE SAL>2500 OR JOB='CLERK' AND DEPTNO>=20;

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3) OR ~ ( ... AND ... )

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SELECT DEPTNO,ENAME,JOB,SAL FROM EMP WHERE SAL>2500 OR (JOB='CLERK' AND DEPTNO>=20);

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3. NOT

1) !=

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SELECT DEPTNO,ENAME,JOB,SAL FROM EMP WHERE JOB != 'CLERK';

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2) NOT IN

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SELECT DEPTNO,ENAME,JOB,SAL FROM EMP WHERE JOB NOT IN ('CLERK','SALESMAN');

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