没有实体框架数据库连接的ASP.NET MVC

Question

I have a project that uses ASP.NET MVC and follows three tier architecture. I want to add a class library that will have a base class which will contain the connection string and in the child class that connection string has to be called by pass the data source as string.

Base class:

public class DALConnection {
     public SqlConnection con = new SqlConnection("Data Source=ABC;Initial Catalog=HotelMgmt;Integrated Security=True");
}

Child class:

public class DataAccessOperation: DALConnection {
    // Some code
}

Instead of this I want to pass the connection string to the base class through child class as string.

Answer 1

Do you think you could use the constructors to do that? (as below)

Base class:

public class DALConnection {

     public SqlConnection con;

     public DALConnection(string connectionString)
     {
          con = new SqlConnection(connectionString);
     }

}

Child class:

public class DataAccessOperation: DALConnection {

    //Some code
    public DataAccessOperation() : base("Data Source=ABC;Initial Catalog=HotelMgmt;Integrated Security=True")
    {

    }
}

Answer 2

Use a constructor to pass the connections strings and have the derived class call the base constructor.

Base class

public class DALConnection {
    protected string connectionString = "Data Source=ABC;Initial Catalog=HotelMgmt;Integrated Security=True";
    public SqlConnection con;

    public DALConnection(string connectionString) {
        if(connectionString!=null)
            this.connectionString = connectionString;
        con = new SqlConnection(this.connectionString);
    }
}

Child class:

public class DataAccessOperation: DALConnection {

    DataAccessOperation(string connectionString) : base(connectionString) {
    }

}

Answer 3

public class DALConnection 
{
      public DALConnection(string _conString)
      {
            if(!String.IsNullOrEmpty(_conString))
            {
                con=new SqlConnection(_conString);
            }
            else 
            {
                //error handling
            }
      }      

      private SqlConnection con;

}

public class DataAccessOperation: DALConnection 
{
      public DataAccessOperation (string _conString) :base (_conString)
      {
      }


}