title: Forcing left join to only return one row from matching Ids in the right table
body: <p>I have two tables in which I'd like to join, the right table sometimes has more than 1 row for each ID. But I'm not interested to have all the matches, only the first one is enough. </p>
  
  <p>How can I do that? </p>
  
  <p>Example: </p>
  
  <p>Foo:</p>
  
  <pre><code>     Id             FooColumns....
       100             xxxxxxxx
       200             xxxxxxxx
       300             xxxxxxxx
       400             xxxxxxxx
  </code></pre>
  
  <p>Bar: </p>
  
  <pre><code>     Id             BarColumns....
       100             yyyyyyyy
       100             zzzzzzzz
       200             yyyyyyyy
       200             zzzzzzzz
  </code></pre>
  
  <p>What I want to have is : </p>
  
  <p>FooBar: </p>
  
  <pre><code>     Id             FooColumns....     BarColumns
       100             xxxxxxxx            yyyyyyyy
       200             xxxxxxxx            yyyyyyyy
       300             xxxxxxxx              nulls
       400             xxxxxxxx              nulls
  </code></pre>
  
  <hr>
  
  <pre><code>Query: 
     Select F.*,B.* from Foo f left join Bar b on f.Id=B.Id   ?? 
  </code></pre>