SQL:Count子句

上述查询生成的结果如下：

SELECT Impressions.Campaign_id as C_id, Verticals.Vertical_Name as V_name
FROM Impressions
Inner Join Verticals ON Impressions.Campaign_id = Verticals.Campaign_id;

我希望它返回垂直_Name列发生次数的计数。在这种情况下，结果应该如下所示：

   C_id            V_name
    ID1            Travel
    ID2            Retail
    ID3             Demo
    ID4             Demo
    ID5            Travel
    ID6             Demo

我该怎么做呢？

您需要的是，而不是

MAX

，然后是垂直名称：

V_id   Count
Demo     3  
Travel   2
Retail   1

SELECT Verticals.Vertical_Name as V_name, COUNT(*) AS [Count]
FROM Impressions
Inner Join Verticals ON Impressions.Campaign_id = Verticals.Campaign_id
GROUP BY Verticals.Vertical_Name