[변수 선택] 특정 변수를 지정하여서 데이터 출력 - 4

4. Display name and salary for all employees.

 

* 전체 직원의 이름(Name)과 급여(sal)를 출력하시요.

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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 Print의 By 구문 , Keep 구문 Python Dfply Package : select 구문 파이썬 Base 프로그래밍 :

 

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1. 오라클(Oracle)

Oracle Programming

select ename, sal 
from   emp;

 

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2. 파이썬(Pandas)

• emp 테이블에서 ename과 sal 변수를 출력

Python Programming

emp[['ename', 'sal']]

 

Results

	ename	sal
0	SMITH	800
1	ALLEN	1600
2	WARD	1250
3	JONES	2975
4	MARTIN	1250
5	BLAKE	2850
6	CLARK	2450
7	SCOTT	3000
8	KING	5000
9	TURNER	1500
10	ADAMS	1100
11	JAMES	950
12	FORD	3000
13	MILLER	1300

 

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3. R Programming (R Package)

• emp 테이블에서 ename과 sal 변수를 출력

R Programming

%%R

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

 

Results

# A tibble: 14 x 2
   ename    sal
   <chr>  <dbl>
 1 SMITH    800
 2 ALLEN   1600
 3 WARD    1250
 4 JONES   2975
 5 MARTIN  1250
 6 BLAKE   2850
 7 CLARK   2450
 8 SCOTT   3000
 9 KING    5000
10 TURNER  1500
11 ADAMS   1100
12 JAMES    950
13 FORD    3000
14 MILLER  1300

 

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4. R Dplyr Package

• emp 테이블에서 ename과 sal 변수를 출력

R Programming

%%R

emp %>% select(ename, sal)

 

Results

# A tibble: 14 x 2
   ename    sal
   <chr>  <dbl>
 1 SMITH    800
 2 ALLEN   1600
 3 WARD    1250
 4 JONES   2975
 5 MARTIN  1250
 6 BLAKE   2850
 7 CLARK   2450
 8 SCOTT   3000
 9 KING    5000
10 TURNER  1500
11 ADAMS   1100
12 JAMES    950
13 FORD    3000
14 MILLER  1300

 

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5. R sqldf Package

• emp 테이블에서 ename과 sal 변수를 출력

R Programming

%%R

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

 

Results

    ename  sal
1   SMITH  800
2   ALLEN 1600
3    WARD 1250
4   JONES 2975
5  MARTIN 1250
6   BLAKE 2850
7   CLARK 2450
8   SCOTT 3000
9    KING 5000
10 TURNER 1500
11  ADAMS 1100
12  JAMES  950
13   FORD 3000
14 MILLER 1300

 

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6. Python pandasql Package

• emp 테이블에서 ename과 sal 변수를 출력

Python Programming

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

 

Results

	ename	sal
0	SMITH	800
1	ALLEN	1600
2	WARD	1250
3	JONES	2975
4	MARTIN	1250
5	BLAKE	2850
6	CLARK	2450
7	SCOTT	3000
8	KING	5000
9	TURNER	1500
10	ADAMS	1100
11	JAMES	950
12	FORD	3000
13	MILLER	1300

 

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7. R data.table Package

• emp 테이블에서 ename과 sal 변수를 출력

R Programming

%%R

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

DT[ , .(ename, sal)]

 

Results

     ename  sal
 1:  SMITH  800
 2:  ALLEN 1600
 3:   WARD 1250
 4:  JONES 2975
 5: MARTIN 1250
 6:  BLAKE 2850
 7:  CLARK 2450
 8:  SCOTT 3000
 9:   KING 5000
10: TURNER 1500
11:  ADAMS 1100
12:  JAMES  950
13:   FORD 3000
14: MILLER 1300

 

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8. SAS Proc SQL

 

SAS Programming

%%SAS sas

PROC SQL inobs=5;
  /* create table statsas as */
    select ename, SAL 
    from   emp;
QUIT;

 

Results

ename	sal
SMITH	800
ALLEN	1600
WARD	1250
JONES	2975
MARTIN	1250

 

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SAS Programming

%%SAS sas

PROC SQL inobs=5;
  select *
  from   emp (KEEP=ENAME SAL);
QUIT;

 

Results

ename	sal
SMITH	800
ALLEN	1600
WARD	1250
JONES	2975
MARTIN	1250

 

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9. SAS Data Step

 

SAS Programming

%%SAS sas

PROC PRINT DATA=EMP(obs=5);
     VAR ENAME SAL;
RUN;

 

Results

OBS	ename	sal
1	SMITH	800
2	ALLEN	1600
3	WARD	1250
4	JONES	2975
5	MARTIN	1250

 

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SAS Programming

%%SAS sas

PROC PRINT DATA=EMP(KEEP=ENAME SAL obs=5);
RUN;

 

Results

OBS	ename	sal
1	SMITH	800
2	ALLEN	1600
3	WARD	1250
4	JONES	2975
5	MARTIN	1250

 

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10. Python Dfply Package

 

Python Programming

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

 

Results

	ename	sal
0	SMITH	800
1	ALLEN	1600
2	WARD	1250

 

 

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