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I'm trying to convert a mongo collection to an R data frame. I'm using rmongodb package to do the same. I'm facing a problem with fields with the datatype "ObjectId" (in the code below, the column "_id"), rmongodb does not seem to recognize them as valid fields and thus excluding them from the OP dataframe. Is there a way to bulk convert ObjectId fields to string or extract their values?

query <- list(
mongo.bson.from.JSON('
{
"$project" : {
"_id" :0,
"app_id" : "$_id",
"column_1" : "$mongo_column_1",
#########################

I've already tried the functions:

ObjectId.toString()

and

ObjectId.valueOf()

But I think I'm making some syntactical errors and can't seem to find the right syntax to work in this situation.

P.S. I'm parsing the entire collection and not individual records.

Attila The Geek
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1 Answers1

4

I had the same problem this morning. Try using the mongo.oid.to.string function.

l = mongo.bson.to.list(mongo.cursor.value(cursor))

k <- mongo.oid.to.string(l[["_id"]])
k
"5242aef73edb350519b2bf3f"
SymbolixAU
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Robert Ben Parkinson
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