Griffin.Data.Mapper.CommandBuilders.CommandBuilder.DeleteCommand C# (CSharp) Method

        public void DeleteCommand(IDbCommand command, object entity)
        {
            if (command == null) throw new ArgumentNullException("command");
            if (entity == null) throw new ArgumentNullException("entity");

            var where = "";
            foreach (var property in _keys)
            {
                var value = property.GetValue(entity);
                if (value == null || value == DBNull.Value)
                    throw new DataException(
                        string.Format("Entity {0}' do not contain a value for the key property '{1}'", entity,
                            property.PropertyName));

                where += string.Format("{0}=" + "@{1} AND ", property.ColumnName, property.PropertyName);
                command.AddParameter(property.PropertyName, value);
            }

            command.CommandText = string.Format("DELETE FROM {0} WHERE {1}",
                TableName,
                @where.Remove(@where.Length - 5, 5));
        }

        public void do_not_allow_DbNull_in_the_delete_query()
        {
            var mapper = Substitute.For<ICrudEntityMapper>();
            mapper.TableName.Returns("Users");
            mapper.Properties.Returns(new Dictionary<string, IPropertyMapping>
            {
                {"Name", new FakePropertyMapping("Name", "real_name")},
                {"Id", new FakePropertyMapping("Id", "id"){Value = DBNull.Value, IsPrimaryKey = true}}
            });
            var command = new AdoNetFakes.FakeCommand();
            var entity = new { Id = "Hello" };


            var sut = new CommandBuilder(mapper);
            Action actual = () => sut.DeleteCommand(command, entity);

            actual.ShouldThrow<DataException>();
        }