postregsql에서 하나 이상의 컬럼을 얻는 방법?

Question

postresql에서 somwthing을 할 수 있습니까?

select min(column1, column2) as Min, max(column1, column2) as Max from mytable; 

Answer 1

옵션 1 :

select CASE when a.min1 < a.min2 then a.min1 else a.min2 END as minimum, 
CASE when a.max1 > a.max2 then a.max1 else a.max2 END as maximum 
from (select min(col1) as min1, min(col2) as min2, max(col1) as max1, 
    max(col2) as max2 from myTable) a 

옵션 2 :

select CASE when MIN(col1) < MIN(col2) THEN MIN(col1) ELSE MIN(col2) END as Minimum, 
    CASE WHEN MAX(col1) > MAX(col2) THEN MAX(col1) ELSE MAX(col2) END as Maximum 
from myTable 

최종 옵션 : 어떻게 이런 일에 대한

select LEAST(MIN(col1),MIN(col2)) as myMinimum, GREATEST(MAX(col1),MAX(col2)) as myMaximum from myTable 

? :)

Answer 2

select 
    min(CASE when a.min1 < a.min2 then a.min1 else a.min2 END) as minimum, 
    max(CASE when a.max1 > a.max2 then a.max1 else a.max2 END) as maximum 
from myTable as a 

Answer 3

LEAST (a, b) sql 함수를 사용하려고합니다.

이

다른 스택 오버플로 질문 How do I get the MIN() of two fields in Postgres?

SELECT LEAST(column1, column2) as Min, 
     GREATEST(column1, column2) as Max 
FROM mytable; 

공식 PostgreSQL의 문서 here입니다에 대답했다.