title: mongoDB Join on multiple fields
body: <p>I am rewriting SQL Queries into mongoDB. Can someone help how do we join two collections with multiple join keys and conditions like in below SQL Query.</p>
  
  <pre><code>SELECT S.* FROM LeftTable S
  LEFT JOIN RightTable R ON S.ID =R.ID AND S.MID =R.MID WHERE R.TIM &gt;0 AND S.MOB IS NOT NULL
  </code></pre>
  
  <p>I have the below code which does with single join key condition. I would be glad if someone can help with multiple join keys and where clause to complete query.</p>
  
  <pre><code>db.dim.aggregate([{$lookup:{from:"dimFactsVer11",localField:"Sub", foreignField:"Type", as:"EmbedUp"}}])
  </code></pre>