如何在MySQL中不顯示負數？

Question

我有這樣的代碼（它的工作原理）：

SELECT sportsID, newsID, cID, SUM(likes) AS totalLikes 
FROM like_table 
GROUP BY sportsID, newsID 
ORDER BY totalLikes DESC 

我試圖修改它不顯示負值，但它不工作。

SELECT sportsID, newsID, cID, SUM(likes) AS totalLikes 
FROM like_table 
WHERE totalLikes > 0 
GROUP BY sportsID, newsID 
ORDER BY totalLikes DESC 

任何人都可以幫忙嗎？我不知道我做錯了什麼。

Answer 1

嘗試使用HAVING條款：

SELECT sportsID, newsID, cID, SUM(likes) AS totalLikes 
FROM like_table 
GROUP BY sportsID, newsID 
HAVING SUM(likes)> 0 
ORDER BY totalLikes DESC 

說明：加入

的HAVING子句SQL因爲WHERE關鍵字無法與合計函數一起使用。

WHERE子句將條件放在選定的列上，而HAVING子句將條件放在由GROUP BY子句創建的組上。

Answer 2

WHERE totalLikes > 0應該是HAVING SUM(likes) > 0並置於GROUP BY子句之後。因此：

SELECT sportsID, newsID, cID, SUM(likes) AS totalLikes 
FROM like_table 
GROUP BY sportsID, newsID 
HAVING SUM(likes) > 0 
ORDER BY totalLikes DESC