1) 使用类中的方法设置连接
//controller
using(Connection conn = new Connection()){
 conn.Open();
 MyClass myclass = new MyClass();
 myclass.setDbConnection(conn);
}
//MyClass in Model
class MyClass {
    Connection conn;
    public setDbConnection(conn){
        this.conn = conn;
    }
    public updateTableA(){
        //using this.conn;
    }
    public updateTableB(){
        //using this.conn;
    }
    public updateTableC(){
        //using this.conn;
    }
}
2) 将连接作为参数传递给每个方法
//controller
using(Connection conn = new Connection()){
 conn.Open();
 MyClass myclass = new MyClass();
}
//MyClass in Model
class MyClass {
    public updateTableA(Connection conn){
        //using conn;
    }
    public updateTableB(Connection conn){
        //using conn;
    }
    public updateTableC(Connection conn){
        //using conn;
    }
}
哪个是正确(或更好)的方式?为什么?