PHP 帮助 : Follow System in Microblogging

Question

我正在制作一个类似于 Instagram 的网站。我对 php 很陌生。我在用户的个人资料中创建了一个关注按钮。

当您已经关注用户时，如何让关注按钮消失？如何用取消关注按钮替换它？

//以下是我的 php 代码

if (isset($_POST['addfriend'])){


    $fromuser = $user;
    $touser = $username;

    if($fromuser == $username){
        $Msg = "You cannot follow yourself<br/>";
    }
    else
    {
        $getID= mysql_query("SELECT userID FROM user WHERE username='$user'");
        $get_ID_row = mysql_fetch_assoc($getID);
        $ID_db = $get_ID_row['userID'];

        $sql = "insert into following (userID, fromUser, toUser) 
        values ('$ID_db','$fromuser', '$touser')";

        $result = mysql_query($sql);

         $Msg= "Success! <br/>";

    }
}
else{
    //Do nothing
}

//我的关注按钮代码

                        <form action="<?php $user;?>" method ="POST">
                        <?php echo $Msg; ?>
                        <input type = "submit" name ="addfriend" value = "Follow"/>
                        </form>

Answer 1

在您要显示“关注”或“取消关注”按钮的页面上，首先运行 MySQL 查询以查明您是否已经关注此人:

$sql = "select * from following 
        where userID = $user
        and   fromUser = $fromUser
        and   toUser = $toUser";
$result = mysql_query($sql);

if( $result) {
    if( mysql_num_rows($result) > 0) {
        // if we get here we know we are already following that person
        ....[see below]

现在动态创建您需要的任何按钮:-

    if( mysql_num_rows($result) > 0) {
        // if we get here we know we are already following that person
        echo '<input type = "submit" name ="removefriend" value = "Un-follow"/>';
    }
    else
    {
        echo '<input type = "submit" name ="addfriend" value = "Follow"/>';
    }

在您获得表单结果的下一页上，检查两个按钮:

if (isset($_POST['addfriend'])) {
    ...[do what you already have]
}
else
if (isset($_POST['removefriend'])) {
    ...[do SQL to remove the record from the following table]
}

另请注意，从 PHP v5.5 开始，这种风格的 MySQL 已被弃用。在未来的某个阶段，在它们最终停止支持之前，您将不得不将您的程序转换为 MySQLi 或 PDO_MySQL 扩展。请参阅关于此的 PHP 手册，例如 http://php.net/manual/en/mysqlinfo.api.choosing.php。 .