title: SSRS Report Works when the Parameter uses the "=" Operator but not "IN"
body: <p>I will try to keep this short. </p>
  
  <p>I have a report in SSRS where the @Position parameter needs to be able to accept multiple values (see the parameter in the WHERE clause below). </p>
  
  <pre><code>DECLARE @multiplier INT;
  
  SET @multiplier = 30
  
  SELECT p.Fname, 
         p.Lname,
         p.Position,
         (SUM(plg.PTS)/SUM(plg.MP))*@multiplier AS PTS,
         (SUM(plg.TRB)/SUM(plg.MP))*@multiplier AS TRB,
         (SUM(plg.AST)/SUM(plg.MP))*@multiplier AS AST,
         (SUM(plg.BLK)/SUM(plg.MP))*@multiplier AS BLK,
         (SUM(plg.STL)/SUM(plg.MP))*@multiplier AS STL,      
         (SUM(plg.TOV)/SUM(plg.MP))*@multiplier AS TOV,
         (SUM(plg.FT)/SUM(plg.MP))*@multiplier AS FTs,
         --SUM(plg.FTA)/SUM(plg.MP))*@multiplier AS FTAs,
         SUM(plg.FT)/SUM(plg.FTA) AS FT_Percentage,
         (SUM(plg.FG)/SUM(plg.MP))*@multiplier AS FGs,
         --SUM(plg.FGA)/SUM(plg.MP))*@multiplier AS FGAs,
         SUM(FG)/SUM(FGA) as Field_Percentage,
         (SUM(plg.[3P])/SUM(plg.MP))*@multiplier AS Threes,
         --SUM(plg.[3PA])/SUM(plg.MP))*@multiplier AS TP%
         SUM([3P])/SUM([3PA]) AS Three_Point_Percentage
  FROM PlayerGameLog plg
  INNER JOIN Players p
  ON p.PlayerID = plg.PlayerID
  WHERE plg.PlayerID IN (SELECT PlayerID
              FROM Players
              WHERE lname != 'westbrook')
      AND p.TeamID = 'OKC'
      AND p.Position = @Position
  GROUP BY p.Fname, p.Lname, p.Position
  ORDER BY PTS DESC;
  </code></pre>
  
  <p>If I change the following line:</p>
  
  <pre><code>AND p.Position = @Position
  </code></pre>
  
  <p>To:</p>
  
  <pre><code>AND p.Position IN @Position
  </code></pre>
  
  <p>I get a message that prompts me to <a href="https://i.stack.imgur.com/EnFBc.png" rel="nofollow noreferrer">Define Query Paramters</a>.  No matter what I set those to, I encounter a message that says <a href="https://i.stack.imgur.com/iuY53.png" rel="nofollow noreferrer">there is an error.</a>  I've changed the parameter to allow multiple values, and still no dice.  Any ideas? </p>