FillDataTable method of business object accept System.Data.Common.DbCommand. I use this method to run commands.

Do I handle provider specific properties "SqlCommand and SqlParameter", "OracleCommand and OracleParameter" with my coding or any other alternative exists in the framework. 

I'm trying to write a query class (But complex query text is supplied with XML documents) with parameters. The paramters will be extracted with parsing the query. For the parameters collection, I will need provider specific parameter class.

What should I do ? Should I follow same way as with command object ?

Other than chaning the object type, you can generally use the same parameter.Value and stick with setting the parameter.DbType property to define the parameter's database type.  There are very few cases where you will have to set the provider-specific type (SqlParameter.SqlDbType or OracleParameter.OracleType).  The DbType is shared by all providers.

Also, when you're creating/converting parameters, remember that some commands use ? as the placeholder for parameters and go off of the order of the parameters, while others use @name or :name for parameters and link off of the name of the parameter.

If you're only going between Oracle and SQL Server, then you'll just have to swap the @ and : since they both use named parameters.  But, if you're using DB2 or Access (or other OLE DB or ODBC connections), then you'll have to ensure the order of the parameters matches the use of them within the command and use ? as the placeholders.