title: MongoDB : Read a file stored using GridFS from MongoDB in Javascript(using Node.JS)
body: <p>In a mongodb from javascript code I am able to insert a file(of any extension) using gridfs, It's stored as fs.chunks &amp; fs.files. Now i want to read this file's stream, but on any of the read opration calls on gridStore its giving error : "this.data.buffer.slice is not a function". I have used mongojs library from Node.JS.</p>
  
  <pre><code>// Write a file into MongoDB - Working fine.
  // Our file ID
  var fileId = new ObjectID();
   // Open a new file
  var gridStore;
  // Create a file and open it
  gridStore = new GridStore(db, fileId, "D:/Files/Sofa 2 N050210.3DS", "w+");
  var data = fs.readFileSync('D:/Files/Sofa 2 N050210.3DS');
  gridStore.open(function (err, gridStore) {
  
  gridStore.write(data, function (err, gridStore) {
  // Flush the file to GridFS
  gridStore.close(function (err, fileData) {
         // Write successfull
    });
   });
  });
  </code></pre>
  
  <p>Now problem is when reading, After Closing gridStore, I tried to open file for reading &amp; it is giving error at read call i.e on line no-4 in below code.</p>
  
  <pre><code>gridStore.close(function (result) {
  var gridStore = new GridStore(db, "test_gs_seek_with_buffer", "r");
  gridStore.open(function (err, gridStore) {
  gridStore.read(5, function (err, data) {
    if(err){
            console.log("Error"); return;
       }
    console.log(data.toString());   
   });
  }); 
  });
  </code></pre>
  
  <p>Please help me find solution or the way to read back the file stored in GridFS (From the javascript code not from the command prompt).</p>