mysql - PHP if statement only half works -

ok know stupid i'm doing wrong. i've been stuck on hour , cannot figure out. starting php excuse newbyness. displaying table of data mysql database. want users can "join" "campaign" , have "join" button display campaigns have not joined.

here code:

<?php //include db connect   include ("/db_con.php");  //campaign list function   function listcampaigns() {     //make connection global     global $con;      //set campaign variables     $campaignquery = mysqli_query($con, "select * campaigns");     while($row = mysqli_fetch_array($campaignquery )) {         $ccampaignid = $row['campaignid'];         $creator = $row['creator'];         $name= $row['name'];         $startdate = $row['startdate'];          //set campaign_bookmark variables         $userid = $_session['userid'];         $bmquery = mysqli_query($con, "select * campaign_bookmarks userid = $userid");         while($bmrow = mysqli_fetch_array($bmquery)) {             $bmuserid = $bmrow['userid'];             $bmcampaignid = $bmrow['campaignid'];         }          //echo list in table         echo "<table border='1'>";         echo "<tr>";         //display join button if userid in campaign bookmarks not match session userid         if($_session['userid'] !== $bmuserid) {             echo "<form action='functions/campaign_bookmark.php' name='bookmarkcampaign' method='post'>              <input type='hidden' name='campaignid' value=" . $row['campaignid'] . ">             <input type='submit' value='join' onclick='clicked();'>             </form>";         }         echo "</tr> <tr>";         echo "<td> dungeon master: </td>";         echo "<td>" . $creator . "</td>"; //campaign creator/dm name         echo "</tr> <tr>";         echo "<td> campaign name:</td>";         echo "<td>" . $name . "</td>"; //campaign name         echo "</tr> <tr>";         echo "<td> start date:</td>";         echo "<td>" . $startdate . "</td>"; //campaign start date         echo "</tr>";         echo "</table>";     } //end of outer while loop   } //end of listcampaigns ?> 

the join button show if user has not joined campaigns. when join button show up, submit data database via campaign_bookmark.php once have joined 1 campaign, join button gone of them. if other info needed please let me know what. appreciated.

the reason button disappears because last test false except 1 condition, when previous query returns no records while loop isn't entered.

at first set

$userid = $_session['userid']; 

then query

$bmquery = mysqli_query($con, "select * campaign_bookmarks userid = $userid"); 

notice new userid = $_session['userid'] inside loop

$bmuserid = $bmrow['userid']; 

so $bmuserid == $bmrow['userid'] == $_session['userid']

which mean false

if($_session['userid'] !== $bmuserid) 

so button not appear no matter what, unless query returns nothing

$bmquery = mysqli_query($con, "select * campaign_bookmarks userid = $userid"); 

so following loop never entered ( 1 makes 3 variables equal each other )

i don't know how should fix it, need rethink logic behind this, pointed out goes wrong.

ps: php code needs cleaning, when html code more php consider closing php tag , embedding php inside normal html, table example become this

<table border='1'>   <tr>     <?php if($_session['userid'] !== $bmuserid): ?>     <?# notice forgot add td here, invalid #?>     <form action='functions/campaign_bookmark.php' name='bookmarkcampaign' method='post'>        <input type='hidden' name='campaignid' value='<?= $row['campaignid']?>'>       <input type='submit' value='join' onclick='clicked();'>     </form>     <? endif; ?>   </tr>   <tr>     <td> dungeon master: </td>     <td><?= $creator ?></td>   </tr>   <tr>     <td> campaign name:</td>     <td><?= $name ?></td>   </tr>   <tr>     <td> start date:</td>     <td><?= $startdate ?></td>   </tr> </table> 

in opinion lot more readable