포스팅 목차
* 파이썬 & R 패키지 호출 및 예제 데이터 생성 링크
[ LENGTH Oracle Function ]
LENGTH 함수는 문자열의 길이를 반환한다.
- 함수 설명 : LENGTH 오라클 함수 링크
1. Oracle(오라클)
사원이름(ename)의 문자열 길이를 측정하여 반환한다.
| Oracle Programming |
select EMPNO,
ENAME,
length(ename) ename_len
from emp
| Results |
EMPNO ENAME ENAME_LEN
------------------------------
7839 KING 4
7698 BLAKE 5
7782 CLARK 5
7566 JONES 5
7788 SCOTT 5
7902 FORD 4
7369 SMITH 5
7499 ALLEN 5
7521 WARD 4
7654 MARTIN 6
7844 TURNER 6
7876 ADAMS 5
7900 JAMES 5
7934 MILLER 6
2. Python Pandas(파이썬)
len() 함수
ename 변수의 길이를 반환한다.
| Python Programming |
import copy
withmooc = copy.copy(emp)
withmooc['ename'].str.len().head(7)
| Results |
0 5
1 5
2 4
3 5
4 6
5 5
6 5
Name: ename, dtype: int64
3. R Programming (R Package)
stringr::str_length
| R Programming |
%%R
withmooc <- emp
sapply(withmooc['ename'],stringr::str_length )
| Results |
ename
[1,] 5
[2,] 5
[3,] 4
[4,] 5
[5,] 6
[6,] 5
[7,] 5
[8,] 5
[9,] 4
[10,] 6
[11,] 5
[12,] 5
[13,] 4
[14,] 6
nchar() 함수
| R Programming |
%%R
nchar(as.character(emp$ename))
| Results |
[1] 5 5 4 5 6 5 5 5 4 6 5 5 4 6
4. R Dplyr Package
stringr::str_length()
| R Programming |
%%R
emp %>%
dplyr::mutate(ename_len = stringr::str_length(ename)) %>%
head(10)
| Results |
# A tibble: 10 x 9
empno ename job mgr hiredate sal comm deptno ename_len
<dbl> <chr> <chr> <dbl> <date> <dbl> <dbl> <dbl> <int>
1 7369 SMITH CLERK 7902 1980-12-17 800 NA 20 5
2 7499 ALLEN SALESMAN 7698 1981-02-20 1600 300 30 5
3 7521 WARD SALESMAN 7698 1981-02-22 1250 500 30 4
4 7566 JONES MANAGER 7839 1981-04-02 2975 NA 20 5
5 7654 MARTIN SALESMAN 7698 1981-09-28 1250 1400 30 6
6 7698 BLAKE MANAGER 7839 1981-03-01 2850 NA 30 5
7 7782 CLARK MANAGER 7839 1981-01-09 2450 NA 10 5
8 7788 SCOTT ANALYST 7566 1982-12-09 3000 NA 20 5
9 7839 KING PRESIDENT NA 1981-11-17 5000 NA 10 4
10 7844 TURNER SALESMAN 7698 1981-09-08 1500 0 30 6
5. R sqldf Package
length() 함수
length 함수를 사용하여서 사원이름(ename)의 문자열 길이를 측정하여 반환한다.
| R Programming |
%%R
sqldf(" select length(ename) ename_len from emp ")
| Results |
ename_len
1 5
2 5
3 4
4 5
5 6
6 5
7 5
8 5
9 4
10 6
11 5
12 5
13 4
14 6
6. Python pandasql Package
length() 함수
length 함수를 사용하여서 사원이름(ename)의 문자열 길이를 측정하여 반환한다.
| Python Programming |
ps.sqldf(" select length(ename) ename_len from emp ").head(7)
| Results |
ename_len
0 5
1 5
2 4
3 5
4 6
5 5
6 5
7. R data.table Package
str_length() 함수
| R Programming |
%%R
DT <- data.table(emp)
DT[, 'tot_len' := str_length(ename)]
| Results |
empno ename job mgr hiredate sal comm deptno tot_len
1: 7369 SMITH CLERK 7902 1980-12-17 800 NA 20 5
2: 7499 ALLEN SALESMAN 7698 1981-02-20 1600 300 30 5
3: 7521 WARD SALESMAN 7698 1981-02-22 1250 500 30 4
4: 7566 JONES MANAGER 7839 1981-04-02 2975 NA 20 5
5: 7654 MARTIN SALESMAN 7698 1981-09-28 1250 1400 30 6
6: 7698 BLAKE MANAGER 7839 1981-03-01 2850 NA 30 5
7: 7782 CLARK MANAGER 7839 1981-01-09 2450 NA 10 5
8: 7788 SCOTT ANALYST 7566 1982-12-09 3000 NA 20 5
9: 7839 KING PRESIDENT NA 1981-11-17 5000 NA 10 4
10: 7844 TURNER SALESMAN 7698 1981-09-08 1500 0 30 6
11: 7876 ADAMS CLERK 7788 1983-01-12 1100 NA 20 5
12: 7900 JAMES CLERK 7698 1981-12-03 950 NA 30 5
13: 7902 FORD ANALYST 7566 1981-12-03 3000 NA 20 4
14: 7934 MILLER CLERK 7782 1982-01-23 1300 NA 10 6
8. Python DuckDB의 SQL
| Python Programming |
%%sql
select empno,ename,
length(ename) ename_len
from emp
LIMIT 6
| Python Programming |
duckdb.sql(" select empno,ename, \
length(ename) ename_len \
from emp \
LIMIT 6 ").df()
| Results |
empno ename ename_len
0 7369 SMITH 5
1 7499 ALLEN 5
2 7521 WARD 4
3 7566 JONES 5
4 7654 MARTIN 6
5 7698 BLAKE 5
| [Oracle, Pandas, R Prog, Dplyr, Sqldf, Pandasql, Data.Table] 오라클 함수와 R & Python 비교 사전 목록 링크 |
| 오라클 SQL 함수(Oracle SQL Function) 목록 리스트 링크 |
| [SQL, Pandas, R Prog, Dplyr, SQLDF, PANDASQL, DATA.TABLE] SQL EMP 예제로 만나는 테이블 데이터 처리 방법 리스트 링크 링크 |
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