What makes sense for this case - the vs interface vs abstract class?

Question

I have a Package table in the database.

A package can be of three types: Package A, Package B and Package C.

All three packages have some common fields, for example, 1) name
2) size
3) weight

Now let's move on to the unique fields:

Packets A and B must contain -
a) a channel

Package C must contain -
a) completion

So, I create a table called "Package" in the database.
The columns of the "Package" will then be:

1) Identifier
2) type (1 = PackageA, 2 = PackageB, 3 = PackageC)
3) name
4) size
5) weight
6) channel (not required for package C)
6) completion (not required for packages A and B)

So, I am creating an abstract class as shown below (ignoring property data types):

public abstract class Package
{
public id;  
public type;
public name;  
public size;    
public weight;  
}

public class PackageA : Package
{
public channel;
}


public class PackageB : Package
{
public channel;
}

public class PackageC : Package
{
public completion;
}

what will i do wrong with this approach? Should a package class be abstract or just a class?
Since I would not want others to work directly on the package class and instead accept packages A, B, C.

EDIT: ? , / "" ( A B) ( C) "" ( C) ( A B), "null" " / ?

Answer 1

, , - , channel PackageA PackageB. , , channel:

public abstract class PackageWithChannel : Package {
    public Channel Channel {get;set;}
}
public class PackageA : PackageWithChannel {
   ...
}
public class PackageB : PackageWithChannel {
   ...
}

channel.

, RDBMS, . , .