Postgresql查詢COUNT和MAX在一起？

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; 

我想要做的就是將max（cnt）作爲額外的列。我知道你可以通過cnt訂購併獲得第一個，但我正在尋找替代品。是否有可能或我必須運行多個查詢？

Answer 1

這應做到：

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;