[변수 선택] 특정 변수를 지정하여서 데이터 출력 - 3

 

3. Display the name and job for all employees.

 

* 전체 직원의 이름과 직업(job)을 출력하시오.

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• 파이썬 & R 패키지 호출 및 예제 데이터 생성 링크

• [변수 선택] 특정 변수를 지정하여서 출력

Oracle           : select 구문 파이썬 Pandas : 열 인덱싱 [,] R 프로그래밍   : 열 인덱싱 [,] R Dplyr Package : Select 구문 R sqldf Package : select 구문 Python pandasql Package : select 구문 R data.table Package : 열 인덱싱 [,] SAS Proc SQL : Select 구문 SAS Data Step : Proc Print , Keep 구문 Python Dfply Package : select 구문 파이썬 Base 프로그래밍 :

 

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1. 오라클(Oracle)

 

Oracle Programming

select ename, job 
from   emp;

 

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2. 파이썬(Pandas)

 

Python Programming

emp[['ename', 'job']]

 

Results

	ename	job
0	SMITH	CLERK
1	ALLEN	SALESMAN
2	WARD	SALESMAN
3	JONES	MANAGER
4	MARTIN	SALESMAN
5	BLAKE	MANAGER
6	CLARK	MANAGER
7	SCOTT	ANALYST
8	KING	PRESIDENT
9	TURNER	SALESMAN
10	ADAMS	CLERK
11	JAMES	CLERK
12	FORD	ANALYST
13	MILLER	CLERK

 

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3. R Programming (R Package)

 

R Programming

%%R

emp[, c("ename","job")]

 

Results

# A tibble: 14 x 2
   ename  job      
   <chr>  <chr>    
 1 SMITH  CLERK    
 2 ALLEN  SALESMAN 
 3 WARD   SALESMAN 
 4 JONES  MANAGER  
 5 MARTIN SALESMAN 
 6 BLAKE  MANAGER  
 7 CLARK  MANAGER  
 8 SCOTT  ANALYST  
 9 KING   PRESIDENT
10 TURNER SALESMAN 
11 ADAMS  CLERK    
12 JAMES  CLERK    
13 FORD   ANALYST  
14 MILLER CLERK    

 

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4. R Dplyr Package

 

R Programming

%%R

emp %>% select(ename, job)

 

Results

# A tibble: 14 x 2
   ename  job      
   <chr>  <chr>    
 1 SMITH  CLERK    
 2 ALLEN  SALESMAN 
 3 WARD   SALESMAN 
 4 JONES  MANAGER  
 5 MARTIN SALESMAN 
 6 BLAKE  MANAGER  
 7 CLARK  MANAGER  
 8 SCOTT  ANALYST  
 9 KING   PRESIDENT
10 TURNER SALESMAN 
11 ADAMS  CLERK    
12 JAMES  CLERK    
13 FORD   ANALYST  
14 MILLER CLERK    

 

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5. R sqldf Package

 

R Programming

%%R

require(sqldf)
sqldf("select ename, job from emp")

 

Results

    ename       job
1   SMITH     CLERK
2   ALLEN  SALESMAN
3    WARD  SALESMAN
4   JONES   MANAGER
5  MARTIN  SALESMAN
6   BLAKE   MANAGER
7   CLARK   MANAGER
8   SCOTT   ANALYST
9    KING PRESIDENT
10 TURNER  SALESMAN
11  ADAMS     CLERK
12  JAMES     CLERK
13   FORD   ANALYST
14 MILLER     CLERK

 

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6. Python pandasql Package

 

Python Programming

ps.sqldf("select ename, job from emp")

 

Results

	ename	job
0	SMITH	CLERK
1	ALLEN	SALESMAN
2	WARD	SALESMAN
3	JONES	MANAGER
4	MARTIN	SALESMAN
5	BLAKE	MANAGER
6	CLARK	MANAGER
7	SCOTT	ANALYST
8	KING	PRESIDENT
9	TURNER	SALESMAN
10	ADAMS	CLERK
11	JAMES	CLERK
12	FORD	ANALYST
13	MILLER	CLERK

 

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7. R data.table Package

 

R Programming

%%R

DT          <- data.table(emp)
dept_DT     <- data.table(dept)

DT[ , .(ename, job)]

 

Results

     ename       job
 1:  SMITH     CLERK
 2:  ALLEN  SALESMAN
 3:   WARD  SALESMAN
 4:  JONES   MANAGER
 5: MARTIN  SALESMAN
 6:  BLAKE   MANAGER
 7:  CLARK   MANAGER
 8:  SCOTT   ANALYST
 9:   KING PRESIDENT
10: TURNER  SALESMAN
11:  ADAMS     CLERK
12:  JAMES     CLERK
13:   FORD   ANALYST
14: MILLER     CLERK

 

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8. SAS Proc SQL

 

SAS Programming

%%SAS sas

proc sql inobs=5;
  select ename, job
  from   emp;
quit;

 

Results

ename	job
SMITH	CLERK
ALLEN	SALESMAN
WARD	SALESMAN
JONES	MANAGER
MARTIN	SALESMAN

 

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9. SAS Data Step

 

SAS Programming

%%SAS sas

proc print data=emp;
     var ename job;
run;

 

Results

OBS	ename	job
1	SMITH	CLERK
2	ALLEN	SALESMAN
3	WARD	SALESMAN
4	JONES	MANAGER
5	MARTIN	SALESMAN
6	BLAKE	MANAGER
7	CLARK	MANAGER
8	SCOTT	ANALYST
9	KING	PRESIDEN
10	TURNER	SALESMAN
11	ADAMS	CLERK
12	JAMES	CLERK
13	FORD	ANALYST
14	MILLER	CLERK

 

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10. Python Dfply Package

• The X DataFrame symbol

Python Programming

emp >> select(X.ename,X.job) >> head(3)

 

Results

	ename	job
0	SMITH	CLERK
1	ALLEN	SALESMAN
2	WARD	SALESMAN

 

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[SQL, Pandas, R Prog, Dplyr, SQLDF, PANDASQL, DATA.TABLE]   SQL EMP 예제로 만나는 테이블 데이터 처리 방법 리스트