title: SQL query include elements who have Null associated with them
body: <p>I'm not sure how to title this question, I am trying to build a query which returns a 
  Count of</p>
  
  <ol>
  <li>Requests</li>
  <li>in a given timeframe</li>
  <li>for a particular set of buildings which I have defined using an IN list</li>
  </ol>
  
  <p>I always want ALL the buildings to appear even if there are no Requests in that time frame. 
  An example might look like this: </p>
  
  <pre>
  | Building  | Requests Count|
  |   BL 1    |     NULL      |
  |   BL 2    |     14        |
  </pre>
  
  <p>I have figured out the query IF there are Requests in the 2 week time frame, but if there are no requests in the timeframe then BL 1 would not be included in the results.</p>
  
  <p>I think I want to put my Date condition right next to the SELECT Field, because when I put it in the WHERE section it the building does is not included in the set. </p>
  
  <p>Any help appreciated. </p>
  
  <p>EDIT: Adding the query below. I have read through the suggested solutions but I am not sure they address the issue. Any more clarification would be much appreciated. </p>
  
  <pre><code>SELECT bl.name, wrs.bl_id, count(wrs.wr_id) as NumWRs
  FROM bl RIGHT JOIN
  --Subquery for Status and groups by workteam and calculates # of days open
  (SELECT Reqs.wr_id, Reqs.date_requested, Reqs.bl_id
    FROM Reqs
    WHERE Reqs.date_requested &gt;= @StartDate AND Reqs.date_requested &lt;=  @EndDate  
    AND Reqs.bl_id IN('B00051', 'B00050', 'B00056', 'B00057', 'B00020', 'B00021', 'B00022', 
    'B00023', 'B00025', 'B00026', 'B00027', 'B00028', 'B00029', 'B00030', 'B00031', 'B00032',
    'B00033', 'B00035', 'B00036', 'B00048', 'B00100', 'B00102', 'B00120', 'B00060', 'B00164',  
    'B00181', '000182', 'B00063', 'B00058')
    )
  ) as wrs ON bl.bl_id = wrs.bl_id
  </code></pre>