Group by 在数据库中的数据和显示不一致时的数据的情况下

Question

我有以下数据库

DriverC    Description     LiabilitiesC    Amount    Date
---------------------------------------------------------
D001       form A to B     0               10.00     8/3
D001       form A to B     1               20.00     9/3
D001       form A to B     1               20.00     10/3
D002       form C to D     1               30.00     11/3

LiabilitiesC 是一个有两个值的期权，即：0-Payment； 1-负债

我想要的显示界面如下

DriverC    Description     Liabilities     Payment    Date
-----------------------------------------------------------
D001       form A to B     40.00           10.00      8/3
D002       form C to D     30.00           0          11/3

代码分组如下

var list = (from l in liabilites.AsEnumerable()
                    group l by l.DriverC
                    into g
                    select new LiabilitiesViewModel()
                    {
                        DriverC = g.First().DriverC,
                        Description = g.First().Description,
                        LiabilitiesC = g.First().LiabilitiesC,
                        Amount = g.First().Amount,
                        Date = g.First().Date,
                    }).ToList();

如下分配数据

for (int i = 0; i < list.Count; i++)
            {
                row["DriverC"] = list[i].DriverC;
                row["Description"] = list[i].Description;
                row["Date"] = list[i].Date;
                if (list[i].LiabilitiesC == "0")
                {
                    row["Payment"] = list[i].Amount;
                    row["Liabilities"] = 0;
                }
                else
                {
                    row["Liabilities"] = list[x].Amount;
                    row["Payment"] = 0;
                }
            }

但是，结果并不像预期的那样

DriverC    Description     Liabilities     Payment    Date
-----------------------------------------------------------
D001       form A to B     40.00                      8/3
D002       form C to D     30.00                      11/3

在这种情况下有人帮助我，谢谢

Answer 1

以下代码将对您有所帮助，

var result = from a in liabilites
             group a by a.DriverC into g             
             select new {
                    DriverC = g.First().DriverC,
                    Description = g.First().Description,
                    Liabilities = g.Where(x=>x.LiabilitiesC == 1).Sum(a=>a.Amount)??0,
                    Payment = g.Where(x=>x.LiabilitiesC == 0).Sum(a=>a.Amount)??0,
                    Date = g.First().Date
             };          
Console.WriteLine(result);

你可以使用Where来设置支付是0还是1的条件，然后你可以用Sum总结满足条件的Amount。

Answer 2

试试这个

    void bind()
    {

        string str = "select Driverc,Description,case when Liabilitiesc=0 then 'Payment' else 'Liabilities' end as Type,Amount,Date from Yourtable name";
        SqlCommand cmd = new SqlCommand(str, con);
        SqlDataAdapter da = new SqlDataAdapter(cmd);
        DataTable dt = new DataTable();
        da.Fill(dt);
        if (dt.Rows.Count != 0)
        {
            ClintUsr.DataSource = dt;
            ClintUsr.DataBind();
         use for group which field you want-->   ShowingGroupingDataInGridView(Gridview1.Rows, 2, 1);

        }
        else
        {
            DataTable dt1 = new DataTable();
            dt1.Columns.Add(new DataColumn("Yourdatacolum names", typeof(string)));

            dt1.Rows.Add(dt1.NewRow());
            Gridview1.DataSource = dt1;
            Gridview1.DataBind();

        }


    }

显示 GroupingDataInGridview

void ShowingGroupingDataInGridView(GridViewRowCollection gridViewRows, int startIndex, int totalColumns)
    {
        if (totalColumns == 0) return;
        int i, count = 1;
        ArrayList lst = new ArrayList();
        lst.Add(gridViewRows[0]);
        var ctrl = gridViewRows[0].Cells[startIndex];
        for (i = 1; i < gridViewRows.Count; i++)
        {
            TableCell nextTbCell = gridViewRows[i].Cells[startIndex];
            if (ctrl.Text == nextTbCell.Text)
            {
                count++;
                nextTbCell.Visible = false;
                lst.Add(gridViewRows[i]);
            }
            else
            {
                if (count > 1)
                {
                    ctrl.RowSpan = count;
                    ShowingGroupingDataInGridView(new GridViewRowCollection(lst), startIndex + 0, totalColumns - 1);
                }
                count = 1;
                lst.Clear();
                ctrl = gridViewRows[i].Cells[startIndex];
                lst.Add(gridViewRows[i]);
            }
        }
        if (count > 1)
        {
            ctrl.RowSpan = count;
            ShowingGroupingDataInGridView(new GridViewRowCollection(lst), startIndex + 0, totalColumns - 1);
        }
        count = 1;
        lst.Clear();
    }

Answer 3

我不知道这是否有帮助，但您可以在一个简单的 SQL 查询中完成所有操作，如下所示：

SELECT DriverC,
    Description,
    SUM(CASE WHEN LiabilitiesC = 1 THEN Amount ELSE 0 END) AS Liabilities,
    SUM(CASE WHEN LiabilitiesC = 0 THEN Amount ELSE 0 END) AS Payment,
    MIN(Date) AS Date
FROM Liabilities
GROUP BY DriverC, Description

这还有一个好处是可以在 SQL 服务器上执行计算。