[SQL]-(044) 데이터분석 함수로 순위의 비율 출력하기

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[Reference] 초보자를 위한 SQL 200제

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[SQL 문법]

전체 데이터에서 특정 데이터의 순위의 비율을 출력할 수 있다.

cursor.execute("""
SELECT ename, job, sal, RANK() over (ORDER BY sal DESC) 순위,
                        DENSE_RANK() over (ORDER BY sal DESC) as DENSE_RANK,
                        CUME_DIST() over (ORDER BY sal DESC) as CUM_DIST
  FROM emp

[예시]

# 오라클 연동 및 접속
import pandas as pd
import cx_Oracle
dsn=cx_Oracle.makedsn('localhost',1521,'orcl')
db=cx_Oracle.connect('scott','tiger')
cursor=db.cursor()

# SQL 문법
cursor.execute("""
SELECT ename, job, sal, RANK() over (ORDER BY sal DESC) 순위,
                        DENSE_RANK() over (ORDER BY sal DESC) as DENSE_RANK,
                        CUME_DIST() over (ORDER BY sal DESC) as CUM_DIST
  FROM emp
""")

row=cursor.fetchall()
colname=cursor.description
col=[]

for i in colname:
    col.append(i[0])

# pandas를 사용한 데이터 프레임 형식으로 변환
emp=pd.DataFrame(row,columns=col)
print(emp)

[결과]

     ENAME        JOB     SAL  순위  DENSE_RANK  CUM_DIST
0     KING  PRESIDENT  5000.0   1           1  0.071429
1    SCOTT    ANALYST  3000.0   2           2  0.214286
2     FORD    ANALYST  3000.0   2           2  0.214286
3    JONES    MANAGER  2975.0   4           3  0.285714
4    BLAKE    MANAGER  2850.0   5           4  0.357143
5    CLARK    MANAGER  2450.0   6           5  0.428571
6    ALLEN   SALESMAN  1600.0   7           6  0.500000
7   TURNER   SALESMAN  1500.0   8           7  0.571429
8   MILLER      CLERK  1300.0   9           8  0.642857
9     WARD   SALESMAN  1250.0  10           9  0.785714
10  MARTIN   SALESMAN  1250.0  10           9  0.785714
11   ADAMS      CLERK  1100.0  12          10  0.857143
12   JAMES      CLERK   950.0  13          11  0.928571
13   SMITH      CLERK   800.0  14          12  1.000000