title: Why does this Update query add records?
body: <p>I have two databases, n and p. Below is the Update query I'm trying to use. I would like it to add dates and project numbers from n to p. For some reason after I run the query I end up with more records in p then I began with. What is going on here?</p>
  
  <pre><code>UPDATE DatesAndProjectNumbers
  
  AS n 
  
  LEFT JOIN Projects 
  
  AS p 
  
  ON (n.[Customer Number] = p.[Customer Number]) 
  
  AND (n.[Measure Received] = p.[Measure Received]) 
  
  SET p.PO = [n].[PO], p.[PGI/Invoice] = [n].[PGI/Invoice], p.Cancelled = [n].[Cancelled];
  </code></pre>