How to use mongoimport to import csv
I was perplexed with a similar problem where mongoimport did not give me an error but would report importing 0 records. I had saved my file that didn't work using the OSX Excel for Mac 2011 version using the default "Save as.." "xls as csv" without specifying "Windows Comma Separated(.csv)" format specifically. After researching this site and trying the "Save As again using "Windows Comma Separated (.csv)" format, mongoimport worked fine. I think mongoimport expects a newline character on each line and the default Mac Excel 2011 csv export didn't provide that character at the end of each line.
Your example worked for me with MongoDB 1.6.3 and 1.7.3. Example below was for 1.7.3. Are you using an older version of MongoDB?
$ cat > locations.csv
Name,Address,City,State,ZIP
Jane Doe,123 Main St,Whereverville,CA,90210
John Doe,555 Broadway Ave,New York,NY,10010
ctrl-d
$ mongoimport -d mydb -c things --type csv --file locations.csv --headerline
connected to: 127.0.0.1
imported 3 objects
$ mongo
MongoDB shell version: 1.7.3
connecting to: test
> use mydb
switched to db mydb
> db.things.find()
{ "_id" : ObjectId("4d32a36ed63d057130c08fca"), "Name" : "Jane Doe", "Address" : "123 Main St", "City" : "Whereverville", "State" : "CA", "ZIP" : 90210 }
{ "_id" : ObjectId("4d32a36ed63d057130c08fcb"), "Name" : "John Doe", "Address" : "555 Broadway Ave", "City" : "New York", "State" : "NY", "ZIP" : 10010 }