title: How to perform a LEFT JOIN in SQL Server between two SELECT statements?
body: <p>I have two SELECT statements in SQL Server like these:</p>
  
  <pre><code>(SELECT [UserID] FROM [User])
  (SELECT [TailUser], [Weight] FROM [Edge] WHERE [HeadUser] = 5043)
  </code></pre>
  
  <p>I want to perform a LEFT JOIN between these two SELECT statements on [UserID] attribute and [TailUser] attribute. I want to join existent records in second query with the corresponding records in first query and NULL value for absent records. How can I do this?</p>