如何让用户帖子出现在页面上？

Question

I want every time someone posts something that post to appear below the one that already exists. If I use this it only replace the last post. How should I do it?

<?php
session_start();
$db = mysqli_connect("localhost", "root", "", "store");
if (isset($_POST['button'])) {
    session_start();
    $title= mysqli_real_escape_string($db, $_POST['title']);
    $body= mysqli_real_escape_string($db, $_POST['body']);
    $sql = "INSERT INTO content (title,body) VALUES ('$title', '$body')"; 
    mysqli_query($db, $sql);
    $_SESSION["title"] = $title;
    header("location: home.php");
}
?>

And on the page that I want to display:

<?php
    session_start();
    php echo $_SESSION["title"];
?>

Answer 1

You have to redirect the page to the home.php on any condition but you have not done that.

if mysqli_query() after execution returns FALSE or TRUE the header location will be done and that is not advisable. Since you are needing to echo the SESSION variable over to the home.php page.

You can check condition like this if needed.

if(mysqli_query($db, $sql))
{
// Here you can handle the TRUE loop
$_SESSION["title"] = $title;
header("location: home.php");
}
else
{
// Here you can handle the FALSE loop
}

And in the home.php you have make the following modifications in order to display the session variable to print.

Check Points to print the session variable in other page

1. Ensure that you have session_start() at the top of the page since you need to get the super global variable over to that page.
2. If you need to show anything that is queried from the DB you need to ensure the connection of DB over to that page.
3. If any header Location error occurs try to restart your output buffering over to the page where you have started you header location. You can restart your output buffering with the help of ob_start()
4. ob_start() must be used only if you get header already sent error in the redirection problems.

Usage of ob_start() :

Thinking of ob_start() as saying "Start remembering everything that would normally be outputted, but don't quite do anything with it yet."

Example:

ob_start();
echo("Welcome User!"); //would normally get printed to the screen/output to browser
$output = ob_get_contents();
ob_end_clean();

ob_start() - Turn on output buffering

This function will turn output buffering on. While output buffering is active no output is sent from the script (other than headers), instead the output is stored in an internal buffer.

The contents of this internal buffer may be copied into a string variable using ob_get_contents() . To output what is stored in the internal buffer, use ob_end_flush(). Alternatively, ob_end_clean() will silently discard the buffer contents.

Returns TRUE on success or FALSE on failure.

And over to the question you have made you have to make some changes

You have started the session and that is good but you have appended the php to the echo statement and that looks incorrect.

Replace:

php echo $_SESSION["title"];

with:

echo $_SESSION["title"];

Rather all the other codes are fine.

And to the whole the Entire page will look like this.

<?php
session_start();
$db = mysqli_connect("localhost", "root", "", "store");
if (isset($_POST['button'])) {
    //session_start(); This is not needed at all already you have started the session.
    $title= mysqli_real_escape_string($db, $_POST['title']);
    $body= mysqli_real_escape_string($db, $_POST['body']);
    $sql = "INSERT INTO content (title,body) VALUES ('$title', '$body')"; 
    mysqli_query($db, $sql);
    $_SESSION["title"] = $title;
    header("location: home.php");
}
?>

home.php

<?php
    session_start();
    echo $_SESSION["title"];
?>

Note: Your Code is at SQL Injection vulnerability it is advised to use of the prepared statements along with mysqli.*

Prepared Statements Reference for Mysqli: - http://php.net/manual/en/mysqli.prepare.php .

I think my explanation would be clear for you to rectify your Error and code pretty good.

Thanks & Happy coding:)