如何從SQL查詢中刪除重複值

Question

我想知道如何從sql查詢的輸出中刪除重複值。

這是SQL查詢：

$query = "SELECT useraccount.Username, tariff.Name as tariffs, 
energyconsumption.ElecEnergy, useraccount.Username as User 
    FROM useraccount 
    INNER JOIN tariff 
ON useraccount.tariffs = tariff.id 
INNER JOIN energyconsumption 
ON energyconsumption.User = useraccount.id 
WHERE Date = CURRENT_DATE"; 

這是查詢的輸出：

{"results":[{"Username":"absc868","TariffName":"s1","ElecConsump":"2000"}, 
{"Username":"absc868","TariffName":"s1","ElecConsump":"1900"}]} 

正如你所看到的，查詢篩選出其中數據今天的日期相匹配的數據。我們有2個輸出給同一個用戶。資費名稱和用戶名的值相同，但能耗值不同，這很好。

我想達到以下的輸出：

= {"results":[{"Username":"absc868","TariffName":"s1","ElecConsump":"2000 +1900"} 


= {"results":[{"Username":"absc868","TariffName":"s1","ElecConsump":"3900"} 

可能有人點我的我怎麼能做到這一點的方向是什麼？

非常感謝您閱讀帖子並貢獻的人！

Answer 1

你應該使用和以及一組

$query = "SELECT useraccount.Username as Username, tariff.Name as TariffName, 
sum(energyconsumption.ElecEnergy) as ElecConsump 
    FROM useraccount 
    INNER JOIN tariff 
ON useraccount.tariffs = tariff.id 
INNER JOIN energyconsumption 
ON energyconsumption.User = useraccount.id 
WHERE Date = CURRENT_DATE 
GROUP BY useraccount.Username, tariff.Name as tariffs"; 

（你有表的列名的別名和對象屬性名之間的一些差異）

Answer 2

可以使用group_concat功能：

$query = "SELECT useraccount.Username, tariff.Name as tariffs, 
GROUP_CONCAT(energyconsumption.ElecEnergy SEPARATOR ' +') 
    FROM useraccount 
    INNER JOIN tariff 
ON useraccount.tariffs = tariff.id 
INNER JOIN energyconsumption 
ON energyconsumption.User = useraccount.id 
WHERE Date = CURRENT_DATE 
GROUP BY useraccount.Username, tariff.Name";