public class Column
    {
        public int Id { get; set; }
        public int TableId { get; set; }
        public string Name { get; set; }
        public int MaxLength { get; set; }
        public string Comment { get; set; }
        public bool IsNullable { get; set; }
    }

public class ColumnViewModel : ViewModelBase
    {

        #region members
        private Column _field;
        #endregion

        #region constructors
        public ColumnViewModel(Column field)
        {
            _field = field;
        }
        #endregion

        #region PropertyNames

　　　　 public string MaxLengthPropertyName = "MaxLength";
　　　　 public string CommentPropertyName = "Comment";
　　　　 public string IsNullablePropertyName = "IsNullable";

　　　　 #endregion

        #region public Properties
        public int Id
        {
            get { return _field.Id; }
        }

        public int TableId
        {
            get { return _field.TableId; }
        }

        public string Name
        {
            get { return _field.Name; }
        }

        public int MaxLength
        {
            get { return _field.MaxLength; }
            set
            {
                if (_field.MaxLength == value) return;
                _field.MaxLength = value;
                RaisePropertyChanged(MaxLengthPropertyName);
            }
        }

        public string Comment
        {
            get { return _field.Comment; }
            set
            {
                if (_field.Comment == value) return;
                _field.Comment = value;
                RaisePropertyChanged(CommentPropertyName);
            }
        }

        public bool IsNullable
        {
            get { return _field.IsNullable; }
            set
            {
                if (_field.IsNullable == value) return;
                _field.IsNullable = value;
                RaisePropertyChanged(IsNullablePropertyName);
            }
        }
        #endregion

<DataGrid Name="DgrdColumns" Grid.Row="1" Grid.Column="0" AutoGenerateColumns="False">
            <DataGrid.Columns>
                <DataGridTextColumn Header="Name" Binding="{Binding Name}" Width="150"></DataGridTextColumn>
                <DataGridTemplateColumn Header="MaximumLength">
                    <DataGridTemplateColumn.CellTemplate>
                        <DataTemplate>
                            <TextBox Text="{Binding MaxLength, Mode=TwoWay}"></TextBox>
                        </DataTemplate>
                    </DataGridTemplateColumn.CellTemplate>
                </DataGridTemplateColumn>
                <DataGridTemplateColumn Header="Comment" Width="150">
                    <DataGridTemplateColumn.CellTemplate>
                        <DataTemplate>
                            <TextBox Text="{Binding Comment, , Mode=TwoWay}"></TextBox>
                        </DataTemplate>
                    </DataGridTemplateColumn.CellTemplate>
                </DataGridTemplateColumn>
            </DataGrid.Columns>
        </DataGrid>

void BindData()
        {
            #region datas
            _columns = new List<Column>
            {
                new Column()
                {
                    Id = 1,
                    TableId = 2,
                    Name = "first",
                    Comment = "first comment",
                    IsNullable = true
                },
                new Column()
                {
                    Id = 2,
                    TableId = 2,
                    Name = "second",
                    Comment = "second comment",
                    IsNullable = true
                },
                new Column()
                {
                    Id = 3,
                    TableId = 2,
                    Name = "third",
                    Comment = "third comment",
                    IsNullable = false
                }
            };
            #endregion

            viewModels = new ObservableCollection<ColumnViewModel>(_columns.Select(x => new ColumnViewModel(x)));
            DgrdColumns.ItemsSource = viewModels;
        }