π μμμ vs λͺ
μμ νλ³ν
| κ΅¬λΆ |
μ€λͺ
|
μμ |
| μμμ νλ³ν |
Oracleμ΄ μλμΌλ‘ λ°μ΄ν° νμ
μ λ³ν |
WHERE salary = '5000' β λ¬Έμμ΄μ΄ μλμΌλ‘ μ«μλ‘ λ³νλ¨ |
| λͺ
μμ νλ³ν |
λ³ν ν¨μλ₯Ό μ¬μ©νμ¬ μ§μ νμ
λ³κ²½ |
TO_CHAR(hire_date, 'YYYY-MM-DD')TO_DATE('2025-06-01', 'YYYY-MM-DD')TO_NUMBER('123.45') |
λͺ
μμ νλ³ν ν¨μ μμ½
| ν¨μ |
μ€λͺ
|
μμ |
TO_CHAR(date, 'fmt') |
λ μ§ β λ¬Έμμ΄ |
TO_CHAR(SYSDATE, 'YYYY-MM-DD') |
TO_DATE(str, 'fmt') |
λ¬Έμμ΄ β λ μ§ |
TO_DATE('2025-06-01', 'YYYY-MM-DD') |
TO_NUMBER(str) |
λ¬Έμμ΄ β μ«μ |
TO_NUMBER('123.45') |
λ μ§ ν¬λ§· μμ
λ μ§ κ΄λ ¨
| ν¬λ§· |
μλ―Έ |
μμ μΆλ ₯ |
YYYY |
μ°λ 4μ리 |
2025 |
YY |
μ°λ 2μ리 |
25 |
MM |
μ (2μ리) |
06 |
MON |
μ μ½μ΄ |
JUN |
MONTH |
μ μ 체 μ΄λ¦ |
JUNE |
DD |
μΌ (2μ리) |
24 |
DY |
μμΌ μ½μ΄ |
MON |
DAY |
μμΌ μ 체 μ΄λ¦ |
MONDAY |
μκ° κ΄λ ¨
| ν¬λ§· |
μλ―Έ |
μμ μΆλ ₯ |
HH |
μ (12μκ°μ ) |
03 |
HH24 |
μ (24μκ°μ ) |
15 |
MI |
λΆ |
07 |
SS |
μ΄ |
45 |
AM / PM |
μ€μ /μ€ν |
PM |
μμ SQL μ½λ
-- λ μ§λ₯Ό λ¬Έμλ‘ λ³ν
SELECT first_name,
TO_CHAR(hire_date, 'MM/YY/DD') AS month_hired,
hire_date
FROM employees
WHERE first_name = 'Steven';
-- λ¬Έμμ΄μ λ μ§λ‘ λ³ν
SELECT TO_DATE('2025-06-01', 'YYYY-MM-DD') AS converted_date
FROM dual;
-- λ¬Έμμ΄μ μ«μλ‘ λ³ν
SELECT TO_NUMBER('123.45') AS converted_number
FROM dual;
π FMμ΄ μμ λ vs μμ λ
| ν¬λ§· |
μ€λͺ
|
μΆλ ₯ μμ |
'YYYY"λ
MMμ DDμΌ"' |
κΈ°λ³Έ ν¬λ§· (곡백 ν¬ν¨) |
2025λ
06μ 01μΌ (β MM, DDλ νμ 2μ리) |
'FMYYYY"λ
MMμ DDμΌ"' |
μ°λ μ 곡백 μ κ±° |
2025λ
06μ 01μΌ |
'FMYyyy"λ
" FMMon"μ" FMDd"μΌ"' |
μμ리 0 μ κ±° + 곡백 μ κ±° |
2025λ
6μ 1μΌ |
β
μμ λΉκ΅