PHP PDO fetch null

Question

How do you check if a columns value is null? Example code: ``` $db = DBCxn::getCxn(); $sql = "SELECT exercise_id, author_id, submission, result, submission_time, total_rating_votes, total_rating_values FROM submissions LEFT OUTER JOIN submission_ratings ON submissions.exercise_id=submission_ratings.exercise_id WHERE id=:id"; $st = $db->prepare($sql); $st->bindParam(":id", $this->id, PDO::PARAM_INT); $st->execute(); $row = $st->fetch(); $this->total_rating_votes = $row['total_rating_votes']; if($this->total_rating_votes == null) // this doesn't seem to work even though there is no record in submission_ratings???? { ... } ```

Accepted Answer

Thanks for all of your answers. After a bit of experimentation this code solved my problem

```
$this->total_rating_votes = $row['total_rating_votes'];

if(!isset($this->total_rating_votes)) // this is now true if this record had a NULL value in the DB!!!
{
...
}
```

PHP PDO fetch null

Solution

Problem