title: not including null values in sql join
body: <p>I have two tables CustomerAddress(CustomerId, City, Country) and CustomerTransactions(TransactionId, CustomerId, CustomerContact). Here are the values in the tables:</p>
  
  <p>For CustomerAddress:</p>
  
  <pre><code>1001, El Paso, USA    
  1002, Paris, France    
  1003, Essen, Germany    
  </code></pre>
  
  <p>For CustomerTransactions:</p>
  
  <pre><code>98, 1001, Phillip    
  99, 1001, NULL
  100, 1001, NULL    
  101, 1003, Carmen    
  102, 1003, Carmen    
  103, 1003, Lola    
  104, 1003, NULL    
  105, 1002, NULL
  </code></pre>
  
  <p>I'm trying to join both tables and have the following result set:</p>
  
  <pre><code>1001, El Paso, USA, Phillip    
  1002, Paris, France, (empty string)    
  1003, Essen, Germany, Carmen    
  1003, Essen, Germany, Lola
  </code></pre>
  
  <p>It seems like a simple join but I'm having trouble coming up with the above result set. Please help.</p>
  
  <p>Thanks.</p>