如何从表MySQL中获取特定列的特定行的总和？

Question

在这里，我试图从mysql表的特定列中的15行中总共获取5个特定行。

$sql = "SELECT SUM(column) FROM Table WHERE business_name= 'my business'";
$result = $conn-> query($sql);
$row = $result -> fetch_assoc();

print_r ($row);

Array ( [SUM(rating)] => )  

Answer 1

尝试Count(*)

$sql = "SELECT COUNT(*) AS 'column' FROM Table WHERE business_name= 'my business'";

Answer 2

您必须使用别名。 $sql = "SELECT SUM(column) as ss FROM Table WHERE business_name= 'my business'"; 然后使用$row['ss']获取数据

$sql = "SELECT SUM(column) as ss FROM Table WHERE business_name= 'my business'";
$result = $conn-> query($sql);
$row = $result -> fetch_assoc();
echo $row['ss'];

希望对您有所帮助！