>>There is SqlDbType.VarChar data type, but System.String type. So, for all char data it will be System.String type.
>
>Well, this causes a problem, as when I use a database which is not bound to my data dictionary, I need to rely on what the DataTable will return. So, I need to be able to differentiate between a string and a varchar.

not knowing what kind of DD you use, I'd argue that you should code it in a way that if the runtime usage cannot rely on a explicit DD, such info should be loaded dynamically to be always available to your code - via SqlDataReader.GetDataTypeName() for instance