// creates user-table column
        public override string CreateUserTableColumn(DataContext sourceDataContext, DataContext targetDataContext, UserTableColumn userTableColumn, bool firstColumn = false)
        {
            var builder    = new StringBuilder();
            var definition = DataTypes.ConvertDataTypeDefinition(sourceDataContext, targetDataContext, userTableColumn);

            if (string.IsNullOrEmpty(definition))
            {
                return(null);
            }

            builder.Append(firstColumn ? "    " : "  , ");
            builder.Append(definition);
            return(builder.ToString());
        }