Changing video thumbnail_link in Facebook

Can I update or change the thumbnail_link for a video in Facebook?

I access the video attributes with this query:

$facebook->api(array('method' => 'fql.query', 'quer开发者_如何学JAVAy' => "SELECT vid, thumbnail_link FROM video WHERE owner='$user_id' AND vid=22170513xxxxx" ));

Now, if I want to change the thumbnail image for the video, how can I do it? I tried the FQL:

'query' => "UPDATE video SET thumbnail_link ='xyz'  WHERE owner='$user_id' AND vid=22170521xxxx"

But it doesn't work, so what can be the process?

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FQL is only for querying data exposed by the Graph API, so you can only fetch data. You can read the documentation in Facebook Query Language (FQL).

Queries are of the form:

SELECT [fields] FROM [table] WHERE [conditions].