How to recall items from favourites table - php

Question

I have a table of favourites with 'id' 'userid' and 'postid'. I'm trying to select all the entries in 'postid' when 'userid' = 1 for example.
I also have a table of posts with 'id' and others of content. I then want to select all the rows where a 'postid'='id' and then echo the content of those rows.
Essentially filtering the posts by which have been favourited by the user.
What I've got is
<?php
include 'connect.php';
$user = $_SESSION['id'];
$getfaves = mysql_query("SELECT postid FROM Favourites where userid='$user'") or die(mysql_query());
if ($rowfave = mysql_fetch_assoc($getfaves))
{
$faveposts = $rowfave['id'];
$getposts = mysql_query("SELECT * FROM Posts where id='$faveposts' ORDER BY id DESC");
while ($row = mysql_fetch_assoc($getposts))
{
$content = 'content';
echo ($content);
}
}
?>
(the $content = 'content'; is just an example, it's not what I'm actually using in my code)
Obviously this is incorrect, probably because I want to select a list of ids and then search for everything in that list, but I've only coded to look for one item. However I don't know how to correct this.
Thanks in advance for any assistance.

Answer 1

there is a more simple way to do that using just one sql query with the help of INNER JOIN.
so your query will be
SELECT POST.*
FROM `Favourites`
INNER JOIN `Post`
ON Post.id = Favourites.postid WHERE (Favourites.userid='$user')
ORDER BY Post.id DESC;
here is doc about INNER JOIN and its utilities
Please let me know if you need more help,
the php part:
<?php
include 'connect.php';
$user = $_SESSION['id'];
$sql="SELECT POST.*
FROM `Favourites`
INNER JOIN `Post`
ON Post.id = Favourites.postid WHERE (Favourites.userid='$user')
ORDER BY Post.id DESC";
$conn = new mysqli($servername, $username, $password,$dataBase);
$Result = $conn->query($sql);
while($row = $Result->fetch_assoc()) {
//do what you want with the $row, it contain ur resault
}
?>
feel free to test it and report the problem if there is one