MySQL的順序排名爲列

我有一個MySQL查詢，從多個表中選擇數據，然後下令基於如下一些任意標準的結果：MySQL的順序排名爲列

SELECT [columns] FROM (
    SELECT *, COUNT(*) as `matches` 
    FROM [table1] 
    JOIN [table2] USING (id) 
    JOIN [table3] USING (id) 
    WHERE [criteria] 
    GROUP BY `id` 
    ORDER BY `matches` DESC 
) AS `grouped` 
ORDER BY (
    (CASE WHEN [1st rank criteria] THEN 3 ELSE 0 END) + 
    (CASE WHEN [2nd rank criteria] THEN 2 ELSE 0 END) + 
    (CASE WHEN [3rd tank criteria] THEN 1 ELSE 0 END) 
) DESC 
LIMIT 100

這工作得很好，但我的問題是：我可以將排名分數顯示爲列？我已經着眼於嘗試使用變量，但我對SQL很陌生，所以這些都超出了我的想象。

對不起，如果這是一個明顯的問題，但非常感謝您的時間和協助。

來源

2011-09-04 Superangel

試試這個：

SELECT [columns], 
    (
    (CASE WHEN [1st rank criteria] THEN 3 ELSE 0 END) + 
    (CASE WHEN [2nd rank criteria] THEN 2 ELSE 0 END) + 
    (CASE WHEN [3rd tank criteria] THEN 1 ELSE 0 END) 
    ) AS MyRank 

FROM (
    SELECT *, COUNT(*) as `matches` 
    FROM [table1] 
    JOIN [table2] USING (id) 
    JOIN [table3] USING (id) 
    WHERE [criteria] 
    GROUP BY `id` 
    ORDER BY `matches` DESC 
) AS `grouped` 
ORDER BY MyRank DESC 
LIMIT 100;

來源

2011-09-04 06:01:11

完美！我沒有意識到CASE可以按照這個順序排列。非常感謝您的及時和有用的回覆！ – Superangel

把它放在選擇

((CASE WHEN [1st rank criteria] THEN 3 ELSE 0 END) + 
(CASE WHEN [2nd rank criteria] THEN 2 ELSE 0 END) + 
(CASE WHEN [3rd tank criteria] THEN 1 ELSE 0 END)) as ranking

來源

2011-09-04 05:59:36 miki

非常感謝您！你是絕對正確的。我感謝您的幫助。 – Superangel

MySQL的順序排名爲列

回答

相關問題