c# MongoDB RunCommand

Question

Can someone give me an example of the use of the RunCommand method that takes a string argument only (called CommandName) available in the MongoDB .NET driver? I know there is an overloaded RunCommand method that takes an object reference (I think a CommandDocument object) as an argument, but I'd rather not use that one.

I'm having trouble getting the syntax right for CommandName. Thanks in advance!

Answer 1

If you are using some recent version of the official C# driver, the "real" string based version you are referring to ( CommandResult RunCommand(string commandName) ) is only part of the legacy driver component (check the namespace). I would hence not recommend using it.

The "official" interface currently looks like this:

TResult RunCommand<TResult>(Command<TResult> command, /* and some additional optional parameters */)

And since the C# driver heavily relies on implicit type conversions, there also is one from a string (and a BsonDocument ) to the corresponding sub types of Command<TResult> ( JsonCommand<TResult> and BsonDocumentCommand<TResult> ). So you can effectively pass a string to the above new RunCommand() method, too.

You can therefore write either one of the following lines both of which do the exact same thing:

RunCommand<BsonDocument>("{count: \"collection_name\"}")
RunCommand<BsonDocument>(new BsonDocument("count", "collection_name"))