System.Data.Common.SqlDateTimeStorage.Aggregate C# (CSharp) Метод

        public override object Aggregate(int[] records, AggregateType kind)
        {
            bool hasData = false;
            try
            {
                switch (kind)
                {
                    case AggregateType.Min:
                        SqlDateTime min = SqlDateTime.MaxValue;
                        for (int i = 0; i < records.Length; i++)
                        {
                            int record = records[i];
                            if (IsNull(record))
                                continue;
                            if ((SqlDateTime.LessThan(_values[record], min)).IsTrue)
                                min = _values[record];
                            hasData = true;
                        }
                        if (hasData)
                        {
                            return min;
                        }
                        return _nullValue;

                    case AggregateType.Max:
                        SqlDateTime max = SqlDateTime.MinValue;
                        for (int i = 0; i < records.Length; i++)
                        {
                            int record = records[i];
                            if (IsNull(record))
                                continue;
                            if ((SqlDateTime.GreaterThan(_values[record], max)).IsTrue)
                                max = _values[record];
                            hasData = true;
                        }
                        if (hasData)
                        {
                            return max;
                        }
                        return _nullValue;

                    case AggregateType.First:
                        if (records.Length > 0)
                        {
                            return _values[records[0]];
                        }
                        return null;// no data => null

                    case AggregateType.Count:
                        int count = 0;
                        for (int i = 0; i < records.Length; i++)
                        {
                            if (!IsNull(records[i]))
                                count++;
                        }
                        return count;
                }
            }
            catch (OverflowException)
            {
                throw ExprException.Overflow(typeof(SqlDateTime));
            }
            throw ExceptionBuilder.AggregateException(kind, _dataType);
        }