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  • ||와 DISTINCT
    Oracle-diary/QUERY 2020. 1. 30. 17:56
    14:57:11 SQL> SELECT ENAME || ' IS A ' || JOB <- 원화 특수문자 SHIFT를 해주면 ||가 되는데 각각의 열을 이어준다.
    14:57:15 2 FROM EMP;
     
    ENAME||'ISA'||JOB
    -------------------------
    SMITH IS A CLERK <-이어진 모습
    ALLEN IS A SALESMAN
    WARD IS A SALESMAN
    JONES IS A MANAGER
    MARTIN IS A SALESMAN
    BLAKE IS A MANAGER
    CLARK IS A MANAGER
    SCOTT IS A ANALYST
    KING IS A PRESIDENT
    TURNER IS A SALESMAN
    ADAMS IS A CLERK
     
    ENAME||'ISA'||JOB
    -------------------------
    JAMES IS A CLERK
    FORD IS A ANALYST
    MILLER IS A CLERK
     
    14 개의 행이 선택되었습니다.
     
     
     
    14:58:57 SQL> SELECT ENAME || ' IS A ' || JOB "별칭"
    14:59:39 2 FROM EMP ;
     
    별칭
    -------------------------
    SMITH IS A CLERK
    ALLEN IS A SALESMAN
    WARD IS A SALESMAN
    JONES IS A MANAGER
    MARTIN IS A SALESMAN
    BLAKE IS A MANAGER
    CLARK IS A MANAGER
    SCOTT IS A ANALYST
    KING IS A PRESIDENT
    TURNER IS A SALESMAN
    ADAMS IS A CLERK
     
    별칭
    -------------------------
    JAMES IS A CLERK
    FORD IS A ANALYST
    MILLER IS A CLERK
     
     
     
    15:12:33 SQL> SELECT DISTINCT DEPTNO(부서번호) <- DISTINCT는 중복된 것을 제거한다 .
    15:13:31 2 FROM EMP
    15:13:32 3 ;
     
    DEPTNO
    ----------
    30
    20
    10

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