CODEWITHSUNDEEP
phpmysql
doriansm
doriansm

Reputation: 245

PHP if statement only half works

Ok I know this is something stupid I'm doing wrong. But i've been stuck on this for about an hour and cannot figure it out. I am really just starting to get into PHP so excuse the newbyness. Basically I am displaying a table of data from a MySQL database. But I want it so that users can essentially "Join" a "Campaign" and then only have the "Join" button display for campaigns that they have NOT joined.

Here is the 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 * FROM 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 * FROM campaign_bookmarks WHERE 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 does 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 does show up if a user has not joined any campaigns. When the Join button does show up, it does properly submit the data into the database via campaign_bookmark.php But once you have joined one campaign, then the Join button is gone for all of them. If any other info is needed please let me know what. Any help will be VERY appreciated.

Upvotes: 0

Views: 84

Answers (4)

Mohammad AbuShady
Mohammad AbuShady

Reputation: 42899

The reason the button always disappears is because the last test is ALWAYS false except one condition, when the previous query returns no records so the while loop isn't entered.

At first you set 

$userid = $_SESSION['userid'];

Then the query

$bmquery = mysqli_query($con, "SELECT * FROM campaign_bookmarks WHERE userid = $userid");

Notice now the new userid = $_SESSION['userid'] Then inside the loop

$bmuserid = $bmrow['userid'];

so now $bmuserid == $bmrow['userid'] == $_SESSION['userid']

which would mean that this is false

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

So the button will not appear no matter what, unless this query returns nothing

$bmquery = mysqli_query($con, "SELECT * FROM campaign_bookmarks WHERE userid = $userid");

So the following loop is never entered ( the one that makes the 3 variables equal each other )

I don't know how you should fix it, you just need to rethink the logic behind this, I just pointed out where it goes wrong.

PS: your php code really needs some cleaning, when the html code is more than php then consider closing the php tag and embedding php inside normal html, your table for example could become something like this

<table border='1'>
  <tr>
    <?php if($_SESSION['userid'] !== $bmuserid): ?>
    <?# notice you forgot to add a td here, this is 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 my opinion this is a lot more readable

Upvotes: 1

akr
akr

Reputation: 739

The only reason i can see why the buttons wont show up is that your userid is getting overwritten in the session once your submit the new campaign join.

Upvotes: 0

Swann
Swann

Reputation: 2473

Well I might be wrong, but you are performing a SQL request that selects ALL the campaigns based on the userId so : 

$bmuserid = $bmrow['userid'];

Will give you the userId of the current user. so you will always have : 

$bmuserid = $bmtow['userid'];

I would advise you to change your database structure and change the request to directly select all the campaign that are not joined.

Upvotes: 0

Strawberry
Strawberry

Reputation: 33945

Here's something to think about...

SELECT *  
  FROM campaigns c
  LEFT
  JOIN campaign_bookmarks b
    ON b.campaignid = c.campaignid
   AND b.userid = $userid;

Upvotes: 0

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