title: SELECT CASE WHEN & INNER JOIN WHERE NULL or NOT NULL
body: <p>I have following <code>SELECT CASE WHEN</code> query:</p>
  
  <pre><code>SELECT CASE (WHEN TableA.UserId IS NULL) THEN 'CustomString'
  ELSE User.Name 
  FROM TableA
  INNER JOIN User ON A.UserId = User.Id
  </code></pre>
  
  <p>Problem is that it returns only records where I have <code>UserId</code> different than NULL in <code>TableA</code>. But I should also include those records where UserId <code>IS NULL</code> and in that case return "CustomString". What should I add into query to achieve this?</p>