[Oracle] 숫자 함수

//ABS(숫자) : 절대값 구하기

SELECT ABS(-35) FROM DUAL; --35

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// SIGN(숫자) : 음수인지 양수인지 0인지를 알려주는 함수
    ~ 음수: -1
    ~ 양수: 1
    ~ 0 : 0

SELECT SIGN(-35) FROM DUAL; -- -1
SELECT SIGN(35) FROM DUAL; -- 1
SELECT SIGN(0) FROM DUAL; -- 0

---

// ROUND()

- 반올림 함수
- number round(컬럼명) : 정수 반환
- number round(컬럼명, 소수이하 자릿수) : 반올림하여 지정한 소수이하 자릿수까지의 실수 반환

---

select
    height / weight,
    round(height / weight),
    round(height / weight, 1),
    round(height / weight, 2),
    round(height / weight, 3)
from tblComedian;

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// MOD()

- 나머지 함수
- number mod(피제수, 제수)

---

select
    10 / 3,
    mod(10, 3) as "나머지",
    floor(10 / 3) as "몫"
from dual;

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//POWER(숫자, 몇 제곱할지 나타내는 수) : 제곱 반환

// SQRT(숫자) : 제곱근 반환

---

select 
    power(2, 2),
    power(2, 3),
    power(2, 4),
    sqrt(4),
    sqrt(9),
    sqrt(16)
from dual;

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// FLOOR(), TRUNC()

- 절삭 함수
- 무조건 내림 함수
- number floor(컬럼명) : 무조건 정수 반환
- number trunc(컬럼명 [, 소수이하 자릿수]) : 정수 or 실수 반환

---

select
    height / weight,
    floor(height / weight),
    trunc(height / weight),
    trunc(height / weight, 1),
    trunc(height / weight, 2)
from tblComedian;

---

// CEIL()

- 무조건 올림 함수
- number ceil(컬럼명) : 정수 반환 

---

select
    height / weight,
    ceil(height / weight)
from tblComedian;