学习PHP，mysqli_query()查询MYSQL失败，有var_dump($result)查询，返回NULL，求助

Question

<?php
$conn=mysqli_connect("localhost","root","");
mysqli_select_db($conn,"riji");
mysqli_query($conn,"set names utf8");
if($conn){

echo "连接成功";
}else{

echo "连接失改";
}
$result = mysqli_query($conn,"select * from riji_con");
var_dump($result);
?>

Answer 1

$conn这样写：$conn=mysqli_connect("localhost","root","密码","数据库名");

要么mysqli_select_db($conn,"riji");赋给一个变量，mysqli_query()就应该传这个，而不是$conn。
试试吧，应该可以