Class 在 C# 中设计 - DAL

Question

I came across a Data Access Layer Class that was made up entirely of static methods. This class was consumed by a Web Application

For eg

public class DataAccessLayer
{
Public static PersonDetails GetDetails(int iPersonID);
{
//implementation
}
Public static bool SaveDetails(PersonDetails objPerson);
{
//implementation
}

}

Is it a good practice to write such code. I can understand the fact that the performance will be slightly better when I use static methods, but will this cause any concurrency errors when multiple users call the Page?

Answer 1

Static or not, you may get concurrency issues, it depends very much on how the actual code in your data access methods is written (eg use of transactions, are there fields used for concurrency checking in your data source etc.).

Answer 2

Is it a good practice to write such code.

Firing offense in my teams, breaks so many good practices I suggest whoever writes something like that goes to my competitors and works for them.

I can understand the fact that the performance will be slightly better when I use static methods.

Like 0.000000000000000000001%?

but will this cause any concurrency errors when multiple users call the Page?

Depends how the methods are written. It violates object orientation, though, makes dependency injection harder, makes it hard to use proper transactional demarcations under a transaction coordinator and makes it hard to unit test / mock things.

Answer 3

The static variable dies in a standalone application, because the garbage collector cleans all your object because your application has ended.

But if you are using this in a webapplication, your application is not dead until your web server dies. So even if you closes the web browser, your web server is not close. Try to shut down your server and your variable will be no more.