如何从 table mysql 中获取特定列的特定行的总和？

Question

在这里，我试图从 mysql 中 table 的特定列的 15 行中获取总共 5 行特定行。

$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

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！

Answer 2

尝试Count(*)

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