Several while statements for mysql_fetch_array causing unexpected errors

Question

I am having a problem with the while function for a mysql_fetch_array. I have experimented on what to use after the statement and what I have now works better than it did before. I thought i could just run a load of loops inside each other but clearly not. I currently have curly brackets on the first two statements and none on the others, you can see this clearly in the code.

However, what i have now means that having more than one variable after each statement causes the second one to stop working when echoed etc. I am trying to avoid using arrays as variables would be a lot easier to lay out afterwards. Not sure what's going on here. I normally use curly brackets after every statement but that just made the whole thing redundant. What should I do to keep all the variables working? I am not great with PHP yet and thanks for all the help so far!

I am just having a mess around for future purposes so I know i should be using mysqli. I have only recently learnt mysqli so I was just using mysql because i feel more comfortable with it for the time being.

Here is the code anyway:

 //fetch favourited artist(s)
                  $fetchartistFavourite = mysql_query("SELECT * FROM artistfavourites WHERE username = '$username' AND password = '$pass';")or die(mysql_error()); 
                  while ($artistFavourite = mysql_fetch_array($fetchartistFavourite)){
                  $favouritedArtist = $artistFavourite['artistname'];
                  $favouritedArtistUrl = $artistFavourite['artisturl'];

                     //fetch favourite track(s)
                     $fetchtrackFavourite = mysql_query ("SELECT * FROM trackfavourites WHERE username = '$username' AND password = '$pass'")or die(mysql_error()); 
                     while ($trackFavourite = mysql_fetch_array($fetchtrackFavourite)){
                     $favouritedTrack = $trackFavourite['artistname'];
                     $favouritedTrackUrl = $trackFavourite['artisturl'];

                        //Get news from favourited artist(s)
                           //Get updates to bio
                           $fetchupdatedBio = mysql_query ("SELECT * FROM members WHERE artistname = '$favouritedArtist'")or die(mysql_error()); 
                           while ($updatedBio = mysql_fetch_array($fetchupdatedBio))
                           $updatedBio = $updatedBio['bio'];

                           //Get updates to profile pic
                           $fetchupdatedProfile = mysql_query ("SELECT * FROM members WHERE artistname = '$favouritedArtist'")or die(mysql_error()); 
                           while ($updatedProfile = mysql_fetch_array($fetchupdatedProfile))
                           $updatedProfile = $updatedProfile ['image1'];

                           //Get any new pictures
                           $fetchPic = mysql_query ("SELECT * FROM pictures WHERE artistname = '$favouritedArtist'")or die(mysql_error()); 
                           while ($pic = mysql_fetch_array($fetchPic))
                           $pic = $pic['picurl'];

                           //Get any new tracks
                           $fetchTracks = mysql_query ("SELECT * FROM tracks WHERE artistname = '$favouritedArtist'")or die(mysql_error()); 
                           while ($tracks = mysql_fetch_array($fetchTracks))
                           $trackurl = $tracks['trackurl'];
                           $trackname = $tracks['trackname'];

                           //Get any new gigs
                           $fetchGigs = mysql_query ("SELECT * FROM gigs WHERE artistname = '$favouritedArtist'")or die(mysql_error()); 
                           while ($gigs = mysql_fetch_array($fetchGigs))


                           //arrange gig data into format to be echoed
                           $gig = $favouritedArtist.' is playing for the gig ' .$gigs['gigname'].' at ' .$gigs['venue'].' on the '.$gigs['day'].'th of '.$gigs['month'].', '.$gigs['year'];


                           //Get any new sessions
                           $fetchSessions = mysql_query ("SELECT * FROM sessions WHERE artistname = '$favouritedArtist'")or die(mysql_error()); 
                           while ($sessions = mysql_fetch_array($fetchSessions))

                           $sessionName = $sessions ['title'];

                                  //Get new tracks from favourited tracks(s)if the artist has not been favourited
                                  $fetchnewTrack = mysql_query ("SELECT * FROM tracks WHERE artistname = '$favouritedTrack' AND artistname !='$favouritedArtist'")or die(mysql_error()); 
                                  while ($newTrack = mysql_fetch_array($fetchnewTrack))
                                  $trackname2 = $newTrack['trackname'];



                                      //asign all variables into an 
                                      echo $trackname;

                         }
                         }

what exactly was the question? And you shouldn't be using mysqli. You should be using PDO — karka91
– karka91, Commented Jul 29, 2012 at 17:38
I changed the question a bit but basically I don't know what's going on but it seems that having several while statements stops variables working. I heavily researched PDO vs mysqli and mysqli was a better option for the project — Jacob Windsor
– Jacob Windsor, Commented Jul 29, 2012 at 17:42

Jerska · Accepted Answer · 2012-07-30 00:34:22Z

First of all, you should definitely try not to SELECT *, but just the content you need. Like :

SELECT picurl FROM pictures WHERE artistname = '$favouritedArtist'

instead of

SELECT * FROM pictures WHERE artistname = '$favouritedArtist'

In your :

while ($tracks = mysql_fetch_array($fetchTracks))
$trackurl = $tracks['trackurl'];
$trackname = $tracks['trackname'];

There is an error, because you don't need brackets only when there is a single instruction after the while statement.

Idem with your

while ($sessions = mysql_fetch_array($fetchSessions))

with no brackets, you can't do so if there is more than one instruction related to the while.

While are only needed when you know there will be multiple answers in you MySQL request. Since the might be only one user with this username, you don't need a while.

All of this are basics of php and mysql development, a simple google search would have given you the answer. I think you might need to read some more tutorials on basics of php and mysql.

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