3 tier app data access layer business logic layer

Question

hi friends I want to develop 3 tier app but I still confused how to implement it 1. In data access layer could I return datareader? it's the better approach? some people tell it is not good way you better used arrayList. 2. I have one method with 3 transaction inside (insert update delete) I make this in business layer so that the OleDBConnection (open and close) OleDbTransaction placed in business layer and I pass this as parameter to data access layer is that good way? 3. if anyone have the good tutorial especially in C# please tell me. Thanks

Amit Choudhary · Answer

hi friend 1.its good to user sqldatareader in case of you are just binding the data to the databound control nothing else operation you have to perform. but if you have some more operation to performs like navigating back and forth in your dataset then user other collections. 2. yes you are doing good with this approach. Download the attached project. its a small example it will give you some idea how to deal with 3 tier. Please don't forget to mark Do you like this post if it helps you

Amit Choudhary · Answer

yes..sure you are absolutely right Marcellinus . actually this example was from wrox chapters... and it has put the business logics in DAL folder. I too had doubts on this.. I'll give a look at your project and will discuss it with you

Marcellinus Willindra · Answer

hi amit... this is my modul you can compare it to your code and please tell me what is your opinion?

Marcellinus Willindra · Answer

hi Amit thanks for the example but in your code in BLL folder there are Photo.cs and PhotoCollection.cs they are business object aren't they? as far as I know BLL code like this public string GetFirstImage(object collectionID) { try { return PhotoDB.GetFirstImage(collectionID); } catch (Exception ex) { throw ex; } } please forgive me if I wrong i just wanna discuss with u :)

3 tier app, data access layer, business logic layer