title: Cannot applying find() method with Native MongoDB becaus of ID type
body: <p>I have a function that is needed to get results.</p>
  
  <p>When I give 1 as _id filter everything is OK.</p>
  
  <pre><code>collectionPersonnel
       .find({ '_id' : 1 })
       .toArray(function (err, personnel) {
       console.log(personnel);  
    });
  </code></pre>
  
  <p>If I give filter another way for instance user[0]['personnel_id'] -that is store 1- then I get only [] result;</p>
  
  <pre><code>collectionPersonnel
       .find({ '_id' : user[0]['personnel_id'] })
       .toArray(function (err, personnel) {
       console.log(personnel);  
    });
  </code></pre>
  
  <p>And then I've tried another way. But it doesn't work because I used a string(user[0]['personnel_id']) instead of an ObjectID.</p>
  
  <pre><code>var ObjectID = require('mongodb').ObjectID; 
  var personnelPK_Hex = (user[0]['personnel_id']).toHexString(); 
  var personnelPK = ObjectID.createFromHexString(personnelPK_Hex);   
  </code></pre>
  
  <p>What should I do?</p>
  
  <h2>Edit</h2>
  
  <p>All of my codes are below;</p>
  
  <pre><code>module.exports = {
  
      show: function(req, res) {
  
          User.native(function(err, collectionUser) {
              if(err) {
                  console.log("There is no exist a User by current_id");
              };
              collectionUser
              .find({'_id' : req.param('id')})
              .toArray(function (err, user) {
  
                  Personnel.native(function(err, collectionPersonnel) {
                      if(err) {
                          // handle error getting mongo collection
                          console.log("There is no exist a Personel by current _id");
                      };
                      if(!collectionPersonnel) {
                          console.log("There is no exist a Personel by current _id");
                      };
  
                      // var ObjectID = require('mongodb').ObjectID; 
                      // var personnelPK_Hex = (user[0]['personnel_id']).toHexString(); 
                      // var personnelPK = ObjectID.createFromHexString(personnelPK_Hex);                  
  
                      collectionPersonnel
                      .find({ '_id' : user[0].personnel_id })
                      .toArray(function (err, personnel) {
  
                          console.log(personnel);   
                      });
                  });
              });            
          });
      }
  };
  </code></pre>
  
  <p>And console's output is;
  []</p>
  
  <h2>Solved</h2>
  
  <p>Just like apsillers's said. I had given a numeric _id to collection, incorrectly.
  I've fixed _id value and everything is OK.</p>
  
  <p>Thank you all...</p>