我应该使用单例，静态类还是“共享”从多个类连接到数据库？

Question

I am writing Apps that connect to DB. I need be able use DataBase connection from many classes.

class Database
{
  auto MyConnection = new Connection("..."); // create connection

  void calc()
  {
    MyConnection.query("..."); // use it
  }
}

But I need to get access to MyConnection from every class? Should I do Database class static ? Or maybe I should use Singleton patter? Or make MyConnection as shared ?

And for example what about config? Is it's good idea to make it for example shared ?

Or for example can I declare connection statement globally before main? Like:

MySQLPool MyConnection;

void main()
{
//...
}

and then initiate MyConnection from static this() { } or from DB class?

Answer 1

Have a look at the Repository pattern as described here: http://web.archive.org/web/20150404154203/https://www.remondo.net/repository-pattern-example-csharp/

You should be thinking about the architecture of your application. I you go with this approach then I would have a class called db (not static and not singleton) with methods like:

Read
Scaler
Execute
Insert
etc 

Your repository layer should be separate to your domain layer.

In my experience this makes the code testable.