Php Mysql gzip issue

        $db = $this->getContext()->getDB();
        $dbConf = $this->getContext()->getConf()->database;
        $dbh = new PDO("mysql:host=$dbConf->host;dbname=$dbConf->database", $dbConf->username, $dbConf->password);
        $sql = "update runresults set report_html = :report where id = :id";
        $q = $dbh->prepare($sql);
        $q->execute(array(
            ':report'=>gzencode('hello'),
            ':id'=> 1052
        ));

        $sql="SELECT report_html FROM runresults WHERE id = 1052";
        $result = $dbh->query($sql);
        $row = $result->fetch(PDO::FETCH_NUM);
        
        // Example 1
        // report_html is not encoded properly that's why we see an error in browser
        header( 'Content-Encoding: gzip' );
        echo $row[0];
        
        
        // Example 2
        // This code throws a warning saying "error in data"
        echo gzdecode($row[0]);
        
        // Example 3
        // This code works properly
        header( 'Content-Encoding: gzip' );
        echo gzencode('hello');
        
        // Example 4
        // And this works alright too:
        echo gzdecode(gzencode('hello'));