Question

我目前面临的挑战是获取按特定字段对行进行分组的行的总和，然后将结果返回到每个单独的行。

我想做的小组是客户＆amp;集团＆amp;年份并获得金额和月份的金额。

下面是数据集的示例，右边的2列是我要添加的列：

private void button1_click(object sender, eventsargs e)
{
    bool Found = false;

    if (datagridview1.rows.count > 0)
    {
        foreach (datagridview row in datagridview1.rows)
        {
            if (Convert.ToString(row.cells[0].Value) == cmbproductname.text && convert.tostring(row.cells[1].value) == textprice.text)
            {
                row.cell[2].value = convert.tostring(1 + convert.toint16(row.cells[2].value));
                Found = true;
            }
        }
        if (!Found)
        {
            datagridview1.rows.add(cmbproductname.text, txtprice.text, 1);
        }
    }
    else
    {
        datagridview1.rows.add(cmbproductname.text, txtprice.text, 1);
    }
}

我目前的代码结构如下：

Client   Group    Year         Amount   Months     Sum(Amount)   Sum(Months)

Client1  Group1   Current Year    100       3             300           10
Client1  Group1   Current Year    200       7             300           10
Client2  Group1   Year-1          150       1             400           3
Client2  Group1   Year-1          250       2             400           3
Client3  Group1   Year-2          500       11            500           11
Client3  Group2   Year-3          600       12            600           12

因此想要添加交叉申请：

Select 
  Data.Client, data.Group, Calc_field2.Year, data.Amount, Calc_field.Months

From
  (Select [Column adjustments] From [Source] where [criteria]
   Union ALL 
   Select * from [Source#2] where [Criteria]
   ) as Data

Cross Apply
  (Data.[End Date] - Data.[Start Date]) as Calc_Field(Months)
 [Rolling Year formula from Data] as Calc_Field2(Year)

然后将其添加到主要部分

Cross Apply
(Select
    Data.Client, Data.Group, Calc_field2.Year,
    SUM(Data.Amount) as 'SUM Amount',
    SUM(Calc_Field.Months) as 'SUM Months'
 Group by
    Data.Client, Data.Group, Calc_field2.Year
 ) as MONTH_AMOUNT_SUM

我有一种感觉它不会起作用，这可以通过以下方式得到证实：

每个GROUP BY表达式必须至少包含一个不是外部引用的列。

有人会有什么建议可以采取最佳方法吗？

谢谢你，卢卡斯

Answer 1

使用窗口功能。更改的唯一部分是select：

select Data.Client, data.Group, Calc_field2.Year, data.Amount, Calc_field.Months,
       sum(data.amount) over (partition by data.client, data.group, calc_field2.year),
       sum(data.months) over (partition by data.client, data.group, calc_field2.year)

获取行的总和并将结果作为单独的列放回到行中

1 个答案: