無法用PHP中的SUM運算符顯示結果

Question

我可以尋求幫助嗎？我無法展示結果。如果我運行沒有SUM運算符的代碼，它可以正常工作。請幫助，非常感謝。

 $sql1 ="SELECT SUM(SeatAmount) FROM reservation 
      WHERE RsvDate BETWEEN '07/01/2013' AND '07/31/2013'"; 

    $result1 = $con->query($sql1); 

    printf('<td>'); 
    printf('<b>Seat Amount</b><br/>'); 
    while ($row1 = $result1->fetch_object()) 
    { 
     printf(' 

      %d<br/>',$row1->SeatAmount); 
    } 

Answer 1

$sql1 ="SELECT SUM(SeatAmount) AS Total FROM reservation 
     WHERE RsvDate BETWEEN '07/01/2013' AND '07/31/2013'"; 

$result1 = $con->query($sql1); 

printf('<td>'); 
printf('<b>Seat Amount</b><br/>'); 
while ($row1 = $result1->fetch_object()) 
{ 
    printf(' 

     %d<br/>',$row1->Total); 
} 

Answer 2

爲了這工作，你需要一個別名：

SELECT SUM(SeatAmount) AS SeatAmount 

Answer 3

是什麼$row1的結構？

您可以指定什麼和應該像返回：

SELECT SUM(SeatAmount) AS SeatAmount