php-数据库访问--增、删、改

建立一个登录页面

<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>

登录处理脚本

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

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

//写SQL语句
//SQL注入攻击

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

主页面

<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)
    {
        echo "<tr>";
        
        $sex = $v[2]?"男":"女";
        
        //根据名族代号查询名族名称
        $name = NationName($v[3]);
        
        echo "<td>{$v[0]}</td><td>{$v[1]}</td><td>{$sex}</td><td>{$name}</td><td>{$v[4]}</td><td><a href='shanchu.php?c={$v[0]}' onclick="return confirm('确定删除么？')">删除</a></td>";
        
        /*foreach($v as $v1)
        {
            echo "<td>{$v1}</td>";
        }*/
        
        echo "</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];
    }
    
    ?>
    

删除主页元素脚本

<?php
$code = $_GET["c"];

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

$sql = "delete from info where code='{$code}'";

$r = $db->query($sql);

if($r)
{
    header("location:main.php");
}
else
{
    echo "删除失败";
}

添加主页元素脚本

<form action="addchuli.php" method="post">
    <div>代号：<input type="text" name="code" /></div>
    <div>姓名：<input type="text" name="name" /></div>
    <div>性别：
    <input type="radio" name="sex" value="1" checked="checked" />男
    &nbsp;
    <input type="radio" name="sex" value="0" />女
    </div>
    <div>民族：
    <select name="nation">
        <?php
        //造连接对象
        $db = new MySQLi("localhost","root","123","mydb");
        $sql = "select * from nation";
        $result = $db->query($sql);
        $attr = $result->fetch_all();
        
        foreach($attr as $v)
        {
            echo "<option value='{$v[0]}'>{$v[1]}</option>";
        }
        ?>
    </select>
    </div>
    <div>生日：<input type="text" name="birthday" /></div>
    
    <div><input type="submit" value="添加" /></div>
</form>

添加主页元素脚本处理脚本

<?php
$code = $_POST["code"];
$name = $_POST["name"];
$sex = $_POST["sex"];
$nation = $_POST["nation"];
$birthday = $_POST["birthday"];

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

$sql = "insert into info values('{$code}','{$name}',{$sex},'{$nation}','{$birthday}')";

$db->query($sql);

header("location:main.php");