Updating joined tables together results in "multi-part identifier could not be bound"
<p>I am currently trying to update data of two related tables in one query. While it might not be the best idea because of data redundancy, I want to avoid doing a lot of checks for changed data within my application.</p>

<p>These are the tables in use:</p>

<pre><code>Process (Id, Name, Description)
FavoriteProcess (Id, Process_Id, Position, CreatedTime)
</code></pre>

<p>As you see every <code>FavoriteProcess</code> entity is related to a <code>Process</code> and a <code>Process</code> can appear in multiple <code>FavoriteProcess</code> entities.</p>

<p>I'm writing a tool with which I can update the <code>Position</code> property of a <code>FavoriteProcess</code> entity and the <code>Description</code> property of the related <code>Process</code> as well. For this problem I wrote the following stored procedure which is issuing the error:</p>

<pre><code>CREATE PROCEDURE UpdateFavoriteProcess
    -- parameters for the stored procedure
    @Id                     int,
    @ProcessDescription     varchar(256),
    @Position               int
AS
BEGIN
    -- SET NOCOUNT ON added to prevent extra result sets from
    -- interfering with SELECT statements.
    SET NOCOUNT ON;

    -- The update query
    UPDATE fp
    SET p.Description = @ProcessDescription, -- this line is issuing the error
        fp.Position = @Position
    FROM FavoriteProcess AS fp
    INNER JOIN Process AS p ON fp.Process_Id = p.Id
    WHERE fp.Id = @Id
END
GO
</code></pre>

<p>The query is issuing this error:</p>

<blockquote>
  <p>Msg 4104, Level 16, State 1, Procedure UpdateFavoriteProcess, Line 13
  <strong>The multi-part identifier "p.Description" could not be bound</strong>.</p>
</blockquote>

<p>I've tried searching for this problem but none of the 5 related SO questions provided a solution that could solve my problem! I tried...</p>

<ul>
<li>...surrounding all tables and columns with []</li>
<li>...putting brackets () in any possible way around the join statement</li>
</ul>

<p>but none of my attempts succeeded. So I'm really thankful for someone who can help me with this problem!</p>