如何寫兩個select語句在一個查詢的一個結果

Question

如何寫兩個select語句在一個查詢的一個結果，我希望兩個SELECT語句的一個結果相結合的平均

結果查詢，如： -

select (idcount/days) as avg 

QUERY1： -

select distinct COUNT(id) as idcount 
from employee 
where joiningdate between CONVERT(varchar,@fromdate,103) and CONVERT(varchar,@TODATE,103) 

QUERY2： -

select DATEDIFF(d,@FromDate,@todate) as days 

Answer 1

這樣

;WITH CTE AS(
    SELECT COUNT(DISTINCT id) AS idcount 
    FROM employee 
    WHERE joiningdate BETWEEN CONVERT(varchar,@fromdate,103) and CONVERT(varchar,@TODATE,103) 
) 
SELECT idcount/(DATEDIFF(d,@FromDate,@todate)) AS AV 
FROM CTE