php连接数据库成功，但是无法查询到表，为什么？急！！！！！！

[baidu_37087638]

<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<?php
session_start();
$con = mysqli_connect('localhost', 'root', '', 'beauty') or die("error");//连接数据库
if($con){
echo "成功";
}
$name="";
$psd="";
if((isset($_POST['username']))&&(isset($_POST['password']))){
$name=$_POST["username"];
$psd=$_POST["password"];
if($name==""||$psd==""){
echo "<script>alert('请输入用户名或密码！');history.go(-1);</script>";
}

else{
$sql="select * from domuser where username=`$name` and password=`$psd` ";

$result = mysqli_query($con,$sql);
$num = mysql_num_rows($result);
if ($num) {
$row = mysqli_fetch_array($result); //将数据以索引方式储存在数组中
echo "<script>alert('登录成功！');window.location='index.html';</script>";
} else {
/*echo "<script>alert('用户名或密码不正确！');history.go(-1);</script>";*/
}
}
}
?>

[xuzuning]

你没有指定具体的库

[Son_of_a_bitch]

报的什么错啊

[傲雪星枫]

你只是连接成功，但没有选择数据库，所以执行查询出错 <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <?php session_start(); $con = mysqli_connect('localhost', 'root', '', 'beauty') or die("error");//连接数据库 if($con){ echo "成功"; } // 选择数据库为 "test" mysqli_select_db($con,"test") $name=""; $psd=""; if((isset($_POST['username']))&&(isset($_POST['password']))){ $name=$_POST["username"]; $psd=$_POST["password"]; if($name==""||$psd==""){ echo "<script>alert('请输入用户名或密码！');history.go(-1);</script>"; } else{ $sql="select * from domuser where username=`$name` and password=`$psd` "; $result = mysqli_query($con,$sql); $num = mysql_num_rows($result); if ($num) { $row = mysqli_fetch_array($result); //将数据以索引方式储存在数组中 echo "<script>alert('登录成功！');window.location='index.html';</script>"; } else { /*echo "<script>alert('用户名或密码不正确！');history.go(-1);</script>";*/ } } } ?>