数据访问的登陆界面

登录界面的代码：

<!DOCTYPEhtml PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">

<head>

<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />

<title>无标题文档</title>

</head>

<body>

<form action="chuli.php" method="post">

<div>用户名：<input type="text" name="uid" /></div>

<div>密码：<input type="password" name="pwd" /></div>

<div><input type="submit" value="登录" /></div>

</form>

</body>

</html>

　　　　处理页面的php代码：

<?php
$uid = $_POST["uid"];
$pwd = $_POST["pwd"];

//造连接对象
$db = new MySQLi("localhost","root","123","mydb");

//写SQL语句

$sql = "select password from login where username='{$uid}'";

//执行SQL语句
$reslut = $db->query($sql);

$n = $reslut->fetch_row();

if($uid!="" && $pwd !="" )
{
if($n[0]==$pwd)
{
header("location:main.php");
}
else
{
echo "用户名或密码错误！";
}
}
else
{
echo "用户名密码不能为空";
}

　　　　登陆后跳转到的main界面：

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>无标题文档</title>
</head>

<body>

<table width="100%" border="1" cellpadding="0" cellspacing="0">
<tr>
<td>代号</td>
<td>姓名</td>
<td>性别</td>
<td>民族</td>
<td>生日</td>
<td>操作</td>
</tr>

<?php

//造连接对象
$db = new MySQLi("localhost","root","123","mydb");
//写SQL语句
$sql = "select * from info";
//执行SQL语句
$result = $db->query($sql);
//读数据
$attr = $result->fetch_all();

foreach($attr as $v)
{

$sex = $v[2]?"男":"女";

//根据名族代号查询名族名称
$name = NationName($v[3]);

echo "<tr><td>{$v[0]}</td><td>{$v[1]}</td><td>{$sex}</td><td>{$name}</td><td>{$v[4]}</td></tr>";

}

//给一个民族代号，返回民族名称
function NationName($code)
{
//造连接对象
$db = new MySQLi("localhost","root","123","mydb");
//写SQL语句
$sql = "select name from nation where code='{$code}'";
//执行SQL语句
$result = $db->query($sql);

$attr = $result->fetch_row();

return $attr[0];
}

?>

</table>

</body>
</html>

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原文地址：https://www.cnblogs.com/chenshanhe/p/6839253.html