$costTotal
包含了數(shù)據(jù)庫查詢的結(jié)果,它不是一個字符串,但你在使用 echo
。要將結(jié)果作為字符串輸出,你需要從查詢結(jié)果中獲取數(shù)據(jù)。
$connection = connexion(); $query = "SELECT SUM(product_cost) as total FROM product"; $result = $connection->query($query); $data = $result->fetch(PDO::FETCH_ASSOC); $costTotal = $data['total']; echo $costTotal;