Count number of views for each user - mysql

Question

I have table 'viewlogs' which is formed from three field: ViewLogId, VideoId and UserId. ViewLogId has a primary key and AUTO_INCREMENT value. When a user watches a video its value increments. When a user watch a same video the viewLogId increments, but I want this value to increase only once and uniquely. How do I fix this problem. I've attached the table picture.
I used the following php code for updating the view_counts in the "videos" table. The above picture belongs to the viewlogs table.
public function updateStatistics($videoId, $fieldName, $userId)
{
$this->db->reconnect();
$this->db->trans_begin();
$this->db->query("UPDATE videos SET {$fieldName}={$fieldName}+1 WHERE VideoId=?", array($videoId));
if ($fieldName == "ViewCount" && $userId > 0) {
$this->db->insert('viewlogs', array('UserId' => $userId, 'VideoId' => $videoId, 'ViewDateTime' => date('Y-m-d H:i:s')));
}
if ($this->db->trans_status() === false) {
$this->db->trans_rollback();
return false;
} else {
$this->db->trans_commit();
return true;
}
return false;
}

Answer 1

I solved the problem, just need to check the user_id and video_id before updating the view.
public function updateStatistics($videoId, $fieldName, $userId)
{
$this->db->reconnect();
$this->db->trans_begin();
$sql = "SELECT * FROM viewlogs WHERE UserId ={$userId} AND VideoId ={$videoId}";
$query = $this->db->query($sql);
$result = $query->result_array();
if (empty($result)){
$this->db->query("UPDATE videos SET {$fieldName}={$fieldName}+1 WHERE VideoId=?", array($videoId));
if ($fieldName == "ViewCount" && $userId > 0) {
$this->db->insert('viewlogs', array('UserId' => $userId, 'VideoId' => $videoId, 'ViewDateTime' => date('Y-m-d H:i:s')));
}
}
if ($this->db->trans_status() === false) {
$this->db->trans_rollback();
return false;
} else {
$this->db->trans_commit();
return true;
}
return false;
}