结果与我预期的不一样

Question

Now I want to make unfollow button if some one already followed then don't show follow button the browser should be show unfollow button instead of follow button like twitter. I just tested (Unfollow button is appear) there but not working perfectly . it because when i online from (user1) and follow some one it work and follow button changed to unfollow but when i online from (user2) , want to follow same person which followed by (user1) .. From (user2) timeline it showing already followed(Button) please check the code

if(isset($_POST['follow']))
        {
            $checkFollow=mysqli_query($con,"SELECT follower_id FROM follower WHERE user_id='$userid'");

            if(mysqli_num_rows($checkFollow)==0)
            {
                $follow=mysqli_query($con,"INSERT INTO follower(user_id,follower_id) VALUES ('$userid','$followerid')");
                echo "You Followed";
            }
            else
            {
                echo "Sorry! You already followed this profile";
            }
            $isFollowing=True;
        }

        $checkFollow=mysqli_query($con,"SELECT follower_id FROM follower WHERE user_id='$userid'");
        if(mysqli_num_rows($checkFollow))
        {
            $isFollowing=True;
        }

    }

HTML Code is

  <form action="<?php echo $username;?>" method="post">                              
                       <?php
                             if($isFollowing)
                             {
                             echo "<input type='submit' value='Unfollow' name='unfollow' class='unfollow_button'>";
                             }
                             else
                             {
                                echo "<input type='submit' value='Follow' name='follow' class='unfollow_button'>"; 
                             }

                             ?>
                         </form>

Answer 1

I tried guessing your database structure based on your initial code and put up this answer:

if(isset($_POST['follow']))
{
    $id = $_GET['id'];
    $user_query = mysqli_query($con,"SELECT id FROM user_reg WHERE user_name='$id'");  // ($id) is actually $_GET variable

    if(mysqli_num_rows($user_query) > 0) { //make sure you have at least one result for that $id
        $row = mysqli_fetch_assoc($user_query); //fetch the database result
        $userid = $row['id']; //assign the value to the $userId variable
    } else { // die if no user found with that $id
        die("User id not found");
    }

    $followerid=$idd;  // ($idd) is current session (User Logged in)
    $checkFollow=mysqli_query($con,"SELECT follower_id FROM follower WHERE user_id='$userid'");

    if(mysqli_num_rows($checkFollow) == 0) //check if no rows resulted in the $checkFollow query
    {
        //VERY IMPORTANT!!! make sure the column names are correct. You were using follower_id and user_id in the $checkfollow query and the followerid and userid in the INSERT query
        $follow=mysqli_query($con,"INSERT INTO follower (user_id,follower_id) VALUES ('$userid','$followerid')"); 
        echo "Followed";
    }
    else
    {
        die("User already followed");
    }
}


?>

<form action="test.php?id=<?php echo $username;?>" method="post">
    <input type="submit" value="Follow" name="follow" class="follow_button">
</form>

I hope this helps