Question

SELECT 
    sum(qty) as accept,
    (SELECT sum(qty) 
     FROM pile 
     WHERE pf=false) as reject 
FROM pile 
WHERE pf=true;

这是我目前使用的SQL，但我猜它不是最佳做法？我之前使用的另一种选择是SELECT sum(qty) FROM pile GROUP BY pf，但我需要它们作为列而不是行。

还有其他解决方案吗？

Answer 1

单人通过表格。

SELECT 
    sum(CASE WHEN pf = TRUE THEN qty ELSE 0 END) as accept,
    sum(CASE WHEN pf = FALSE THEN qty ELSE 0 END) as reject
FROM pile;

Answer 2

SELECT pileTrue.sumTrue as accept, pileFalse.sumFalse as reject
FROM
(SELECT sum(qty) sumFalse FROM pile WHERE pf=false) as pileFalse,
(SELECT sum(qty) sumTrue  FROM pile WHERE pf=true ) as pileTrue

Answer 3

没有更好，但更具可读性的IMO。

SELECT
accept = (SELECT sum(qty) FROM pile WHERE pf = true),
reject = (SELECT sum(qty) FROM pile WHERE pf = false)

Answer 4

  check it



  select max(accept), max(v2 ) 
    from
    (
              SELECT 
                    sum(qty) as accept,null v2  
                FROM pile 
                WHERE pf=true
                union
                 SELECT null accept,sum(qty) v2  
                     FROM pile 
                     WHERE pf=false
    )
    group by accept,v2

Answer 5

SELECT (SELECT SUM(qty)
          FROM pile
         WHERE pf = true) AS accept,
       (SELECT SUM(qty)
          FROM pile
         WHERE pf = false) AS reject

如何从一个具有不同where子句的表中获得两次sum（）？

5 个答案: