title: MongoDB Aggregation, tabular typ results
body: <p>I have a document model that looks like this </p>
  
  <pre><code>{
      _id: objectId,
      per: [{
          _pid: objectId,
          thing1: sting,
          thing2: string
      }],
      ore: [{
          _oid: objectId,
          thing1: sting,
          thing2: string
      }],
      tre: [{
          _tid: objectId,
          thing1: sting,
          thing2: string
      }]
  }
  </code></pre>
  
  <p>and I want to pull back a tabular representation</p>
  
  <pre><code>[
      {_id,_pid,thing1,thing2},
      {_id,_pid,thing1,thing2},
      {_id,_oid,thing1,thing2},
      {_id,_oid,thing1,thing2},
      {_id,_oid,thing1,thing2},
      {_id,_tid,thing1,thing2}
  ]
  </code></pre>
  
  <p>How would I go about doing this - Im sure it's an aggregation thing</p>