SQL - 替代WITH ... AS

是否有高效對此示例的替代SQL？我不想使用WITH ... AS，這是主要的標準SQL - 替代WITH ... AS

WITH TEMP_TABLE AS (
    SELECT status, COUNT(1) as total FROM XYZ GROUP BY status 
    ) 
SELECT 
     NVL((SELECT TOTAL FROM TEMP_TABLE WHERE STATUS = 'A'),0) AS A_COUNT , 
     NVL((SELECT TOTAL FROM TEMP_TABLE WHERE STATUS = 'B'),0) AS B_COUNT , 
     NVL((SELECT TOTAL FROM TEMP_TABLE WHERE STATUS = 'C'),0) AS C_COUNT , 
     NVL((SELECT TOTAL FROM TEMP_TABLE WHERE STATUS = 'D'),0) AS D_COUNT , 
     NVL((SELECT TOTAL FROM TEMP_TABLE WHERE STATUS = 'E'),0) AS E_COUNT , 
     NVL((SELECT TOTAL FROM TEMP_TABLE WHERE STATUS = 'F'),0) AS F_COUNT 
FROM DUAL;

我讀到類似的問題，但他們使用其他DDL的東西，我只想要一個基本的SQL語句。

來源

2017-04-17 mCeviker

所以，你想知道如何擺脫[CTE（HTTP的：//計算器.com/questions/38775056/creating-a-cte-in-oracle）從你的陳述？ CTE的功能非常強大和高效......你爲什麼想要擺脫它？ – SQLMason

是的，我知道並喜歡它，但理由是騾子平臺不支持它，至少不是一個實際的方式。請檢查此http://stackoverflow.com/a/36877716/2815227 – mCeviker

感謝您的解釋，我不明白 – SQLMason

只需使用條件彙總：

SELECT SUM(CASE WHEN STATUS = 'A' THEN 1 ELSE 0 END) AS A_COUNT , 
     SUM(CASE WHEN STATUS = 'B' THEN 1 ELSE 0 END) AS B_COUNT , 
     SUM(CASE WHEN STATUS = 'C' THEN 1 ELSE 0 END) AS C_COUNT , 
     SUM(CASE WHEN STATUS = 'D' THEN 1 ELSE 0 END) AS D_COUNT , 
     SUM(CASE WHEN STATUS = 'E' THEN 1 ELSE 0 END) AS E_COUNT , 
     SUM(CASE WHEN STATUS = 'F' THEN 1 ELSE 0 END) AS F_COUNT 
FROM XYZ ;

我要指出的是把價值上的不同的行更容易：

select status, count(*) 
from xyz 
group by status;

來源

2017-04-17 13:41:30

在幾秒鐘內的答案:)現在嘗試！在我的情況下，它們是更實際的，他們在同一行，因爲我會truncate結果到一個json對象 – mCeviker

這看起來更快在Oracle謝謝！ – mCeviker

這是一個簡單的PIVOT查詢

select * 
from (select status from XYZ) 
pivot (
    count(*) for status in (
     'A' as a_count, 'B' as b_count, 
     'C' as c_count, 'D' as d_count, 
     'E' as e_count, 'F' as f_count 
));

來源

2017-04-17 13:59:45 krokodilko

已經給出答案是完美的，你應該使用它們。不過，爲了給大家提供一個通用的解決方案（也許你有能力改變其他查詢），這將是這一個：

SELECT 
    NVL((SELECT TOTAL FROM TEMP_TABLE WHERE STATUS = 'A'),0) AS A_COUNT , 
    NVL((SELECT TOTAL FROM TEMP_TABLE WHERE STATUS = 'B'),0) AS B_COUNT , 
    NVL((SELECT TOTAL FROM TEMP_TABLE WHERE STATUS = 'C'),0) AS C_COUNT , 
    NVL((SELECT TOTAL FROM TEMP_TABLE WHERE STATUS = 'D'),0) AS D_COUNT , 
    NVL((SELECT TOTAL FROM TEMP_TABLE WHERE STATUS = 'E'),0) AS E_COUNT , 
    NVL((SELECT TOTAL FROM TEMP_TABLE WHERE STATUS = 'F'),0) AS F_COUNT 
FROM 
    (SELECT status, COUNT(1) as total FROM XYZ GROUP BY status) TEMP_TABLE;

來源

2017-04-17 18:38:16

SQL - 替代WITH ... AS

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