sql - 包含 SQL 列的结果的百分比

Question

我试图获得一个结果，该结果将显示独特的“原因”、它们的数量以及它们占总数的百分比。到目前为止我已经

SELECT DISTINCT Reason, 
       COUNT(Reason) AS Number, 
       CAST(COUNT(Reason) AS float) / CAST(COUNT(*) AS float) AS percentage
FROM DeletedClients

但是，我发现 COUNT(*) 和 COUNT(Reason) 给出相同的结果。所以我的基本问题是，当我在查询中使用不同的时，如何获得总行数？我使用的是 SQL Server 2005

Answer 1

SELECT Reason, 
       COUNT(Reason) AS Number, 
       CAST(COUNT(Reason) AS float) / CAST(t.Total AS float) AS percentage
FROM DeletedClients,
     (SELECT COUNT(*) As Total FROM DeletedClients) t
GROUP BY Reason, Total