retrieve schema info for a SQL statement in sql datatypes

I'd like to retrieve the schema info for a query i'm executing using a sqldataadapter. I can get the .NET datatype and the maxlength (by setting dbadapter.MissingSchemaAction = MissingSchemaAction.AddWithKey (thanks to some prev post!)

but I'd really like to know if the datatype is a varchar, an nvarchar, a varchar(max), a text, smallint, nchar or whatever. and of course I need the length/maxlength of each type.

How can I do this