Some design experience required please.
I'm about to create a 3-tier data-entry application (win forms) and am unsure about the link between Business tier (middle) and Data Access tiers. My impression was that the Data Access tier handles all access to the database and populates class properties in the middle tier. The middle tier therefore has no access to any data objects (dataset, datareader, connections etc).
Most of the literature/code samples I've found have data objects all over the application or have a thin Data Access tier returning a data object to the middle tier for processing.
I'm looking for other developers experiences that I can scale up to larger applications and web applications as future projects are increasing in size compared to current/earlier projects. Links to useful articles are also highly desired.
I've put the maximum points on here as I believe there may be many responses that deserve points.