<SQL>[SELECT][FROM]

[SELECT][FROM]

1. 사용 방법

- 단일 컬럼

select some_colomn01
from some_table01;
 
select 
some_colomn01
from 
some_table01;
 
select some_colomn01 from some_table01;

- 다중 컬럼

select some_colomn01, some_colomn02
from sometable01;
 
select 
some_colomn01, some_colomn02
from 
sometable01;
 
select some_colomn01, some_colomn02 from sometable01;

- 전체 컬럼

select *
from sometable01;
 
select 
*
from 
sometable01;
 
select * from sometable01;

( * 와일드카드 문자 : 전체)

2. 출력 결과 정하기 & 주석

select top 5 some_colomn01
from sometable01;
--MSSQL
 
select some_colomn01
from sometable01
fetch first 5 rows only;
--DB2
 
select some_colomn01
from sometable01
where rownum <= 5;
--oracle
 
select some_colomn01
from sometable01
limit 5;
--MySQl, MariaDB, PostgreSQL, SQLite
 
select some_colomn01
from sometable01
limit 5 offset 2;

- offset은 시작위치를 지정