你可以給每個case語句一個列別名嗎？ SQL，pl/sql

Question

我正在嘗試做一個查詢，它在一列中計算prorata，完整和隨機結果的數量，並將它們顯示在3個分開的列中。

到目前爲止，我想：

SELECT ot.ort_method, 
CASE ot.ort_method 
    WHEN 'PRORATE' THEN '1' AS 'Pro_Rata' 
    WHEN 'COMPLETE' THEN '2' AS 'Complete' 
    WHEN 'RANDOM' THEN '3' AS 'Random' 
END 
FROM orders o, order_tranches ot 
WHERE o.ord_deal_code = 'EM0004357P'; 

不工作。有人知道該怎麼做嗎？

Answer 1

的樣本數據：

with t1 as(
    select 'EM0004357P' ord_deal_code, 'PRORATE' ort_method from dual union all 
    select 'EM0004357P' ord_deal_code, 'COMPLETE' ort_method from dual union all 
    select 'EM0004357P' ord_deal_code, 'PRORATE' ort_method from dual union all 
    select 'EM0004357P' ord_deal_code, 'RANDOM' ort_method from dual union all 
    select 'EM0004357P' ord_deal_code, 'RANDOM' ort_method from dual 
) 

查詢：

SELECT count(decode(o.ort_method, 'PRORATE', 1)) as prorate 
    , count(decode(o.ort_method, 'COMPLETE', 1)) as complete 
    , count(decode(o.ort_method, 'RANDOM', 1)) as random 
FROM t1 o 
WHERE o.ord_deal_code = 'EM0004357P'; 

結果：

Prorate complete random 
    2   1  2