I have these 2 classes that are respectively called: **Malicious** and **MaliciousSmall**:

Code of **Malicious**:

```
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace DataModel.MaliciousCode
{
    public class Malicious : MaliciousSmall
    {
    }
}

```

Code of **MaliciousSmall**:

```
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Diagnostics;
using System.Data;
namespace DataModel.MaliciousCode
{
    public class MaliciousSmall
    {
        public int Id { get; set; }
        public int MaliciousCodeAlertId { get; set; }
        public string SourceId { get; set; }
        public int MalCodeID { get; set; }
        ......................................................
        ......................................................
        ......................................................

        // CONSTRUCTOR:

       public MaliciousSmall(DataRow row)
        {
            Id = int.Parse(row["Id"].ToString());

            MaliciousCodeAlertId = (row["MaliciousCodeAlertId"] is DBNull) ? MaliciousCodeAlertId = -1 : MaliciousCodeAlertId = int.Parse(row["MaliciousCodeAlertId"].ToString());
            SourceId = (row["SourceId"] is DBNull) ? SourceId = "" : SourceId = row["MaliciousCodeAlertId"].ToString();
            MalCodeID = (row["MalCodeID"] is DBNull) ? MalCodeID = -1 : MalCodeID = int.Parse(row["MalCodeID"].ToString());
            Title = (row["Title"] is DBNull) ? Title = "" : Title = row["Title"].ToString();

        ......................................................
        ......................................................
        ......................................................
        }

}

```

My problem is that, after that I have implementet the **MaliciousSmall** class I obtain the following error on the **Malicious** constructor:

> 
> Error 53 'DataModel.MaliciousCode.MaliciousSmall' does not contain a
>  constructor that takes 0
>  arguments C:\Develop\EarlyWarning\public\Implementazione\Ver2\DataModel\MaliciousCode\Malicious.cs 9 18 DataModel
> 
> 
> 

What can I do to solve it?

I tried to create an empty constructor that take a **DataRow** object as paramether, something like it:

```
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Diagnostics;
using System.Data;

namespace DataModel.MaliciousCode
{
    public class Malicious : MaliciousSmall
    {

        public Malicious(DataRow row)
        {

        }
    }
}

```

But I still have the same problem. What am I missing? What can I do to solve?