How to set null value in column of data table of type Integer

You can't assign DBNull to a field in the DataTable. When you allow DBNull in a DataTable, an extra method is generated. In this case: SetParentApplicationRoleIdNull()

for example:

var newRow = DataSet.ChildApplications.NewChildApplicationRow();
newRow.AField = "Some text";
newRow.SetParentApplicationRoleIdNull();
DataSet.ChildApplications.AddChildApplicationRow(newRow);

This is also while checking the value. You can't directly use the 'property' ParentApplicationRoleId, If you want to read it, you'll have the check it first with another generated method: IsParentApplicationRoleIdNull()

for example:

foreach(var row in DataSet.ChildApplications.Rows)
{
    if(!row.IsParentApplicationRoleIdNull())
    {
        Trace.WriteLine($"ParentApplicationRoleId: {row.ParentApplicationRoleId}");
    }
    else
    {
        Trace.WriteLine("ParentApplicationRoleId: is DBNull, and can't be shown");
  }
}

The "?" behind a datatype makes it nullable.

Example:

int? t = null; 

So nzrytmn is right!

You can try setting the NullValue property of the data column to something that is not "(ThrowException)"

Did you try set DataType as Sytem.Int32? May it have to be nullable.

Could you pls check this answer Table is nullable DateTime, but DataSet throws an exception?

Please declare that value as nullable int(int?). then it will accet all null values