用PHP向数据库中实现简单的增删改查（纯代码）

<?php
    $con = mysql_connect("localhost:3306","root","");

    if (!$con) {
        die('Could not connect: ' . mysql_error());
    }

    mysql_select_db("test", $con);

    $result = mysql_query("SELECT * FROM user");

    echo "<table border='1'>
    <tr>
    <th>Username</th>
    <th>Password</th>
    </tr>";

    while($row = mysql_fetch_array($result)) {
        echo "<tr>";
        echo "<td>" . $row['username'] . "</td>";
        echo "<td>" . $row['password'] . "</td>";
        echo "</tr>";
    }
    echo "</table>";

    mysql_close($con);

?>

从服务器中获取用户所有信息（SQL SELECT语句）并以表格形式出现

<?php
    $con = mysql_connect("localhost","root","");
    if (!$con) {
        die('Could not connect: ' . mysql_error());
    }

    mysql_select_db("test", $con);

    mysql_query("DELETE FROM user WHERE username = '$_POST[username]'");

    mysql_close($con);
?>

删除该用户所有信息delete.php

<?php
    $con = mysql_connect("localhost:3306","root","");

    if (!$con) {
        die('Could not connect: ' . mysql_error());
    }

    mysql_select_db("test", $con);

    $sql = "INSERT INTO user (username,password)
    VALUES
    ('$_POST[username]','$_POST[password]')";

    if (!mysql_query($sql,$con)) {
        die('Error: ' . mysql_error());
    }

    echo "1 record added";

    mysql_close($con);

?>

注册一个新用户insert.php

<?php

    $con = mysql_connect("localhost","root","");
    if (!$con) {
        die('Could not connect: ' . mysql_error());
    }

    mysql_select_db("test", $con);

    mysql_query("UPDATE user SET password = '$_POST[password]' WHERE username = '$_POST[username]'");

    mysql_close($con);
?>

修改一个用户密码update.php

<html>
    <head>
        <title>FORM</title>
    </head>
    <body>
        <br />
        <h1>Insert:</h1>
        <form action="insert.php" method="post">
            username:<input type="name" name="username"/>
            <br />
            password:<input type="password" name="password"/>
            <input type="submit" value="submit"/>
        </form>
        <br /><hr /><br />
        <h1>Delete</h1>
        <form action="delete.php" method="post">
            username:<input type="name" name="username" />
            <br />
            Are you sure?<input type="submit" value="sure" />
        </form>
        <br /><hr /><br />
        <h1>Update</h1>
        <form action="update.php" method="post">
            username:<input type="name" name="username"/>
            <br />
            You want to change your password into:<input type="password" name="password"/>
            <input type="submit" value="submit"/>
        </form>
        <br /><hr /><br />
    </body>
</html>

以上三个功能的提交源Operate.html