sql - 集計関数SQLServerにwhere句を含める方法

Question

OK、次のようなテーブルがあります。

ID   AMOUNT      PAID
1    50.00       Y
2    100.00      N
3    200.00      Y

そして、私は次のようなものを見たいです：

Total     Due Paid
350.00    1   2

したがって、私のSQLは次のようになります（私の頭の中では...それはそのようには機能しません。それが私がここにいる理由です）

select sum(amount)
,count(paid where paid='y') as due
,count(paid where paid='n') as paid 
from sometable where something=somethingelse

Answer 1

select sum(amount) as total, 
       sum(case paid when 'N' then 1 else 0 end) as due, 
       sum(case paid when 'Y' then 1 else 0 end) as paid
from sometable where something=somethingelse

Answer 2

もう1つのオプション

SELECT SUM(AMOUNT) AS Total,
       COUNT(CASE WHEN PAID = 'Y' THEN PAID END) AS Paid,
       COUNT(CASE WHEN PAID = 'N' THEN PAID END) AS Due
FROM sometable
WHERE something = somethingelse

SQLFiddle のデモ