phpsqljoinunion

Using two tables. What am I doing wrong here?

I want to create an activity feed system and my feeds (statuses) and friends are in different tables in my database. How do I connect them so that the logged in user can only receive feeds from their friends.

<?php
$sql = "
SELECT * FROM status WHERE author='(friend of logged-in user)' AND type='a'
**UNION** 
SELECT * FROM friends WHERE user1='$user' AND accepted='1' OR user2='$user' AND accepted='1' 
";
$query = mysqli_query($database, $sql);
$statusnumrows = mysqli_num_rows($query);
while ($row = mysqli_fetch_array($query, MYSQLI_ASSOC)) {
    $user1 = $row["user1"];
    $user2 = $row["user2"];
    $accepted = $row["accepted"];
    $statusid = $row["id"];
    $account_name = $row["account_name"];
    $author = $row["author"];
    $postdate = $row["postdate"];
    $postdate = strftime("%b %d, %Y %I:%M %p");
    $data = $row["data"];
    $data = nl2br($data);
    $data = str_replace("&amp;","&",$data);
    $data = stripslashes($data);
    $statusDeleteButton = '';
    if($author == $log_username || $account_name == $log_username ){
        $statusDeleteButton = '<span id="sdb_'.$statusid.'"><a href="#" onclick="return false;" onmousedown="deleteStatus(\''.$statusid.'\',\'status_'.$statusid.'\');" title="DELETE THIS STATUS AND ITS REPLIES">delete status</a></span> &nbsp; &nbsp;';
    }

    $feedlist .= '<div id="status_'.$statusid.'" class="flipwrapper pin">
        <div class="picture">
        <header class="img-btm">
            '.$postdate.'</b><br />
            20 <a href="#">cmts</a>&nbsp;255 <a href="#">likes</a>&nbsp; '.$statusDeleteButton.'
        </header>
        <a href="status_frame.php?id='.$statusid.'"><img id="bound" src="'.$data.'"/></a></div></div>';
}
?>
Solution

  • You definitely don't want a UNION here, but a subquery, more or less like this:

    SELECT * FROM status 
WHERE author in (
        SELECT whateverfieldshouldmapfromfriendstoauthor FROM friends 
        WHERE user1='$user' AND accepted='1' OR user2='$user' AND  accepted='1' 
    ) AND type='a'

    And some general tips: