mysql combine 2列在哪裏條件

我有一個4列（id，發送者，接收者，狀態）的朋友，我需要一個查詢，將統一（團聚，我不知道英文單詞）發送者和接收者列其中發送者和接收者都等於讓說2. 例如表看起來像這樣mysql combine 2列在哪裏條件

| sender | receiver | 
| 2 | 10  | 
| 2 | 8  | 
| 2 | 9  | 
| 6 | 2  | 
| 7 | 3  | 
| 10 | 3  |

而查詢後，將顯示：（第一3行示出因爲發送方= 2，則顯示第四行是因爲接收器是2.其餘行未顯示）

| result | 
| 10 | 
| 8 | 
| 9 | 
| 6 |

來源

2012-02-07 Popescu Marian

好，因爲我需要它，你可以在結果表中看到的，只有包括尊重發件人或/和接收者（不知道）的條件的值等於2. – 2012-02-07 16:28:54

從來沒有想過這個問題。我已經更新了我的答案。 – 2012-02-07 16:32:02

您幾乎擁有正確的關鍵字;聯盟會讓你做你想做的。

SELECT `receiver` as `result` FROM `table` WHERE `sender` = 2 
UNION 
SELECT `sender` as `result` FROM `table` WHERE `receiver` = 2

來源

2012-02-07 16:28:22

爲什麼'>'而不是'='？ – danihp 2012-02-07 16:35:58

對不起，誤讀了這個問題。編輯答案。 – 2012-02-07 16:39:52

select 
case when sender = 2 
then receiver 
else sender 
end 
from friends 
where sender = 2 or receiver = 2

來源

2012-02-07 16:28:35 YXD

這是您的查詢，我希望有你有意義：

Select sender as result 
from friends 
where receiver = 2 
union 
Select receiver as result 
from friends 
where sender = 2

來源

2012-02-07 16:28:39 danihp

SELECT * 
FROM 
    (SELECT sender as iResult 
    FROM friends 
    WHERE receiver = 2 
     UNION 
    SELECT receiver as result 
    FROM friends 
    WHERE sender = 2) c 
ORDER BY c.iResult DESC

來源

2012-02-07 16:31:20

mysql combine 2列在哪裏條件

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