# Client Side Document Matching

## Basic Document Matching (Deprecated)

Warning

This feature will be removed in version 2.0.

The MongoDB C driver supports matching a subset of the MongoDB query specification on the client.

Currently, basic numeric, string, subdocument, and array equality, `$gt`, `$gte`, `$lt`, `$lte`, `$in`, `$nin`, `$ne`, `$exists`, `$type`, `$and`, and `$or` are supported. As this is not the same implementation as the MongoDB server, some inconsistencies may occur. Please file a bug if you find such a case.

To test this, perform a `mongodump` of a single collection and pipe it to the program.

    $ echo "db.test.insert({hello:'world'})" | mongo
    connecting to: test
    WriteResult({ "nInserted" : 1 })
    bye

    $ mongodump -d test -c test -o - | filter-bsondump
    { "_id" : { "$oid" : "537afac9a70e5b4d556153bc" }, "hello" : "world" }