Php MYSQL在sum()的帮助下添加行
我想创建一个SQL语句,将我的全部问题的所有条目加在一起,然后我想显示这个数字 我的SQL如下所示:Php MYSQL在sum()的帮助下添加行,php,mysqli,Php,Mysqli,我想创建一个SQL语句,将我的全部问题的所有条目加在一起,然后我想显示这个数字 我的SQL如下所示: <?php include ("../script/db_connect.php"); $quiz_percentage_total = 'select sum(total_questions) as total from quiz_result where ' . 'quiz_creator = ' . $_SESS
<?php
include ("../script/db_connect.php");
$quiz_percentage_total = 'select sum(total_questions) as total from quiz_result where '
. 'quiz_creator = '
. $_SESSION["id"];
$quiz_percentage_total_number = mysqli_query($con, $quiz_percentage_total);
$show_quiz_percentage_total_number = mysqli_num_rows($quiz_percentage_total_number);
mysqli_close($con);
?>
我的HTML为空,除了所有必要的HTML信息外,HTML代码为:
<?php echo $show_quiz_percentage_total_number; ?>
我是否使用了错误的变量来显示,还是有其他错误?您需要调用fetch函数来从查询中获取数据
$result = mysqli_query($con, $quiz_percentage_total);
$row = mysqli_fetch_assoc($result);
$quiz_percentage_total_number = $row['total'];
行数将始终为
1
,调用mysqli_num_rows()
没有任何意义,谢谢你,这对我帮助最大!