postgresql - Postgresql同时查询COUNT和MAX？

Question

SELECT id,icon,type,cnt 
FROM  capability 
JOIN (
    SELECT s0_.capability_id AS capability_id0 ,
           count(capability_id) as cnt  
    FROM service_offer_capability s0_ 
    INNER JOIN service_offer s1_ ON s0_.service_offer_id = s1_.id 
    WHERE s0_.value <> 'i:0;' AND s1_.service_id = 2 
    GROUP BY s0_.capability_id
) af
ON af.capability_id0=id;

我想要做的就是将 max(cnt) 作为额外的列。我知道您可以通过 cnt 订购并获得第一个，但我正在寻找替代方案。是否有可能或者我必须运行多个查询？

Answer 1

这应该这样做：

SELECT id,
       icon,
       type,
       cnt,
       max(cnt) over () as max_cnt
FROM  capability 
JOIN (
    SELECT s0_.capability_id AS capability_id0 ,
           count(capability_id) as cnt  
    FROM service_offer_capability s0_ 
    INNER JOIN service_offer s1_ ON s0_.service_offer_id = s1_.id 
    WHERE s0_.value <> 'i:0;' AND s1_.service_id = 2 
    GROUP BY s0_.capability_id
) af
ON af.capability_id0=id;