Link pdf with collection/database in Mongodb - mongodb

Question

I am new to MongoDB. I have following data. Empid, Name, Salary, Resume (Resume is in PDF Format).
Now I am able to insert id, name and salary using mongo shell as following.
db.test.insert({empid:100,Name:'Gaurav',Salary:1000});
I am using mongofiles command to upload resume in database.
mongofiles -d test put "C:\resume.pdf"
So I am able to insert data as well as pdf in database.
My question is how to relate/map empid 100 with resume.

Answer 1

As you're using the mongofiles utility to insert in FS grid, files will be put in the collection fs.files (chunks will be stored in fs.chunks). The files have to live in a different collection because grid FS uses a different engine.
Mongofiles works only with file names, so you can either store the file name and query for it like below OR you can parse the utility response after you call it.
After executing your mongofiles command you'll have:
db.fs.files.find();
{
_id: ObjectId('530191f8fc518a0ecdfd45a6'),
filename: "file.pdf",
chunkSize: 262144,
uploadDate: new Date(1392611832917),
md5: "b1ee25bcd665e2d6d7c4f4d6f08f44a3",
length: 40098
}
To link with your employee entry:
> db.test.insert({empid:100,Name:'Gaurav',Salary:1000, file: ObjectId("530191f8fc518a0ecdfd45a6")});
> db.test.find();
{ "_id" : ObjectId("530195bd58f2d10f8b6703a4"), "empid" : 100, "Name" : "Gaurav", "Salary" : 1000, "file" : ObjectId("530191f8fc518a0ecdfd45a6") }
In case you need to also specify the db and collection, use a DB Ref (http://docs.mongodb.org/manual/reference/database-references/)

Answer 2

You have couple options:
Add a field to your employee document that references files collection by _id:
db.test.insert({empid: 100, Name: 'Gaurav', Salary: 1000, fileId: ObjectId("53019397a8f26bc570896972")});
I prefer this option because it lets you use files for different purposes and not pollute it with fields created for specific needs like employee info. When you use mongofiles to put the file it returns back an ID of a newly created document. Use it as a value for fileId. The same will work if you use mongo driver and get back an id.
Add empid field to files collection. GridFS stores files in 2 collections: chunks and files (list of fields is in this doc). Not perfect for the same reason as option 3.
Move all fields from your employee doc to files collection - not the best practice if you plan to use files for anything other than resume storage.