Inserting multiple string into mysql using bind_param - php

Question

I'm retrieving tweets from the twitter api, which i'm trying to save in my database however i keep getting an error, which i cant seem to fix. i've checked the number of parameters is correct and everything should be okay, so i dont see why i get following error:
Fatal error: Call to a member function bind_param() on a non-object
tweets database:
function retrievePlayerTweets(){
global $con;
$query = $con->prepare("Select players.fullname, players.twitter_user, team.id as teamId FROM players, team WHERE players.teamId = team.id");
$query->execute();
$query->bind_result($fullname, $twitter_user, $teamId);
while ($query->fetch()) {
foreach(retrieveUserTweets($twitter_user) as $twitterData) {
$id = $twitterData['id_str'];
$text = $twitterData['text'];
$name = $twitterData['user']['name'];
$dateString = $twitterData['created_at'];
$favoriteCount = $twitterData['favorite_count'];
$date = date('Y-m-d H:i:s', strtotime($dateString));
$insert_tweet = $con->prepare("INSERT IGNORE INTO tweets (`fullname`, `username`, `text`, `created`, `teamId`, `twitterId`, `favoriteCount`) VALUES (?, ?, ?, ?, ?, ?, ?)");
$insert_tweet->bind_param("ssssisi", $name, $twitter_user, $text, $date, $teamId, $id, $favoriteCount);
$insert_tweet->execute() or die(mysqli_error($con));
}
}
}

Answer 1

The problem is with your $con variable which is not connecting to the database, due to which the methods inside cannot be called.
also it is good pratice to add die() function to print error message after call to the execute function in PDO or mysqli, to see error in query use:
if using PDO:
$insert_tweet->execute() or die(print_r($con->errorInfo()));
if using mysqli:
$insert_tweet->execute() or die(mysqli_error($con));