php - 使用php计算mysql数据库中的行数？

Question

这个问题已经有答案了:

SELECT COUNT(*) AS count - How to use this count (5 个回答)

已关闭 2 年前。

我试图计算演示表中的所有行，但出现错误
Catchable fatal error: Object of class mysqli_result could not be converted to string in C:\xampp\htdocs\working_scripts\test_2.php on line 8
我的 php 代码是:

<?php
$con=mysqli_connect("localhost","root","","test");
if (mysqli_connect_errno())
{
echo"Error connecting to database". mysqli_connect_error();
}
$comment_counter=mysqli_query($con,"SELECT COUNT(*) AS total FROM demos");
echo $comment_counter;
?>

Answer 1

您必须使用mysqli_fetch_array

<?php
$con = mysqli_connect("localhost","root","","test");

if (mysqli_connect_errno())
{
    echo"Error connecting to database". mysqli_connect_error();
}

$result = mysqli_query($con, "SELECT COUNT(*) AS total FROM demos");

if($row = mysqli_fetch_array($result))
{
    echo $row["total"];
}
?>