how to give limit in mongoexport in mongodb

[Rahul Mehta]

I want to take backup of only 100 records from a collection how can i
give limit in query -q.

here what i tried giving limit but after giving limit in -q it is not
inserting any record.

mongoexport --host localhost --db test --collection foo -q
"{"limit":"1"}" > a.json
Please suggest how can i give limit number of record in mongoexport

http://www.mongodb.org/display/DOCS/mongoexport

[Karl Seguin]

Can't, though there is a feature request for this at:

https://jira.mongodb.org/browse/SERVER-2033

The only way I can think of is that you wrap it in a little script...write the documents you want to export to a placeholder collection (using ruby or something) and then export that.

Karl

[Brandon Diamond]

Another option is to run the "limit 100" query in a shell script,
retrieve the min and max ObjectIDs in the range (noting that the top 4
bytes of an ObjectID are a timestamp) and then pass the corresponding
range query to mongoexport. A bit round-about but it'll work in a
pinch!

Hope this helps,
Brandon