php - 如何从表mysql中获取特定列的特定行的总和？

Question

这里我试图从 mysql 表的特定列中获取 15 行中的 5 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

尝试计数(*)

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