Undefined variable on empty database row - php

Question

I'm getting this annoying error when my database row is empty,
But the rows are supposed to be empty until i add some values to it.
Any clues whats going wrong ? I tried to disable the problem by adding # before the variables but that doesn't work when they are in a foreach loop.
If I add data to the rows, the problems stops....
any ideas ?
some code.
$tweets = new Tweets();
foreach($tweets->fetch_tweets($_GET['uid']) as $tweet){
#$tweet_name = $tweet['username'];
#$tweet_date= $tweet['date'];
#$tweet_email= $tweet['email'];
}
function fetch_tweets($uid){ /*Mine and users I follow*/
$uid = (int)$uid;
$query = $this->link->query("SELECT user.id,
user.email,
user.username,
tweets.message,
tweets.date,
userdetails.profile_img,
userdetails.firstname,
userdetails.lastname,
following.id, following.user_id,
following.follow_id
FROM user
LEFT JOIN following ON user.id = following.user_id
JOIN userdetails ON user.id = userdetails.user_id
JOIN tweets ON userdetails.user_id = tweets.user_id
WHERE user.id='{$uid}' OR
user.id IN (SELECT follow_id
FROM following
WHERE following.user_id = '{$uid}' ) GROUP BY tweets.date ORDER BY tweets.date DESC "
);
$tweet = array();
while(($row = $query->fetch(PDO::FETCH_ASSOC)) !==FALSE) {
$tweet[] = $row;
} echo $query->rowCount();
return $tweet;
}

Answer 1

You need to check if the returned array is empty before you try to use it.
$tweets = new Tweets();
$res = $tweets->fetch_tweets($_GET['uid']);
if( empty($res) ) {
echo "no tweets.";
} else {
foreach($res as $tweet){
$tweet_name = $tweet['username'];
$tweet_date = $tweet['date'];
$tweet_email= $tweet['email'];
}
}
Also, you should always declare your functions before calling them. It's not a requirement in PHP as it is in most other languages, but it makes your code much easier to read.

Answer 2

Just run a code to check if number of rows is 0 before fetching the rows