[英]My SQL DISTINCT and count if
我有一張桌子:
我想編寫一個查詢來為特定用戶顯示唯一的Adid:
SELECT DISTINCT Adid FROM Message WHERE (MesFrom =1 OR MesTo = 1) AND (MesFrom =2 OR MesTo = 2) ORDER BY ID DESC
這沒問題
但現在我想添加新消息的數量,所以我需要類似的東西
SELECT Count(IF(New=1,1,0)) AS countNew FROM Message
但需要將它與之前的查詢結合起來
輸出必須如下:
43新3 44新1
請幫忙!)
嘗試
SELECT Adid, SUM(New = 1) new
FROM Message
WHERE (MesFrom = 1 OR MesTo = 1)
AND (MesFrom = 2 OR MesTo = 2)
GROUP BY Adid
輸出:
| ADID | NEW | |------|-----| | 42 | 2 | | 43 | 3 | | 44 | 1 |
這是SQLFiddle演示
SELECT DISTINCT Adid , Count(IF(New=1,1,0)) AS countNew
FROM Message
WHERE (MesFrom =1 OR MesTo = 1) AND (MesFrom =2 OR MesTo = 2)
ORDER BY ID DESC
請檢查它是否正常工作。
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.