title: mongoexport without _id field
body: <p>I am using mongoexport to export some data into .json formatted file, however the document has a large size overhead introduced by _id:IDVALUE tuples. </p>
  
  <p>I found a similar post <a href="https://stackoverflow.com/questions/5594436/is-there-a-way-to-retrieve-data-from-mongodb-without-the-id-field">Is there a way to retrieve data from MongoDB without the _id field?</a> on how to omit the _id field when retrieving data from mongo, but not exporting. It is suggested to use: <code>.Exclude("_id")</code>. I tried to reqrite the --query parameter of mongoexport to somehow include the <code>.Exclude("_id")</code> parameter, but all of the attempts failed so far.</p>
  
  <p>Please suggest what is the proper way of doing this, or should I revert to using some post-export techniques?</p>
  
  <p>Thanks</p>