How to pass the object instead of individual parameters to Data access layer?

If you DAL won't recognise you're business object (presumably because you don't reference the BLL dll in your DAL) then you don't have much option unless you alter your DAL.

Create a properties class where define all the related properties.

and assign all the values to this object. send this object to the DAL class.

For ex: Properties class is EmployeeListDTO, where i am having EmployeeId, EmployeeName, Designation properties.

import properties namespace in DAL,BAL and UI.
in BAL or UI ,


assign variables like below

EmployeeDAL objEmployeeDAL = new EmployeeDAL();
EmployeeListDTO objemployeelistDTO = new EmployeeListDTO();
objemployeelistDTO.EmployeeId = 1;
objemployeelistDTO.EmployeeName = "jagadeesh";
objemployeelistDTO.Designation = "SSE";

objEmployeeDAL.InsertEmployee(objemployeelistDTO);

thats it

you should define this "InsertEmployee" method in DAL.

If I refer BO layer in DAL then it leads circular reference. And also I am refering the upper layer (BO) in lower layer (DAL) which I don't want to do.
Now is there any way with interfaces? If Yes, How?

Thank you.