[使用数据表求和的重复行值

Question

我有这样的数据表

而且我想像这样将所有重复的姓名的薪水总和：

注意：我需要所有列。谁能建议该怎么做？

Answer 1

        DataTable dt = yourDataTableBefore();

        var query = from uu in dt.AsEnumerable()
                    select new
                    {
                        Name= uu.Field<string>("Name"),
                        Salary = uu.Field<string>("Salary"),
                        Date = uu.Field<string>("Date"),
                        Description = uu.Field<string>("Description"),
                    };
        var result = query.GroupBy(cc => cc.Name).Select(dd => new
        {
            Name = dd.Key,
            Salary = string.Join(",",
            dd.Select(ee => ee.Salary).ToList()),
            Date = dd.Select(ee => ee.Date),
            Description = dd.Select(ee => ee.Description),
        });

        DataTable dt_After = new DataTable();
        dt_After.Columns.Add("Name", typeof(string));
        dt_After.Columns.Add("Salary", typeof(string));
        dt_After.Columns.Add("Date", typeof(string));
        dt_After.Columns.Add("Description", typeof(string));

        foreach (var item in result.ToList())
        {
            var newRow = dt_After.NewRow();
            Array.ForEach(item.GetType().GetProperties(), p => newRow[p.Name] = p.GetValue(item, null));
            dt_After.Rows.Add(newRow);
        }
        foreach (DataRow row in dt_After.Rows)
        {
            List<string> List= row["Salary"].ToString().Split(',').ToList();
            string Sum_Salary = //Iterate through the list, convert them to int and sum it up;
            row["Salary"] = Sum_Salary;
        }

Gridview.DataSource = dt_After;
Gridview.DataBind();

您可以在“ var query”中求和，或使用此long方法（以后可以使用数据）。两者都会起作用。我将迭代部分留给您弄清楚（您的功课应该很容易吗，：P）。

希望对您有帮助，最好的问候。

Answer 2

尝试一下。 Ive基本上将具有匹配名称的旧数据表中的行进行了分组，然后对薪水求和，然后使用新分组创建了新数据表。

DataTable new_Table = new DataTable();
        new_Table.Columns.Add("Name");
        new_Table.Columns.Add("Salary");
        new_Table.Columns.Add("Date");
        new_Table.Columns.Add("Description");

        var groupedByState = old_datatable.AsEnumerable()
            .GroupBy(r => r.Field<String>("Name"));
        foreach (var group in groupedByState)
        {
            DataRow maxPremRow = group.OrderByDescending(r => r.Field<String>("Name")).First();
            DataRow newRow = new_Table.Rows.Add();
            newRow.SetField("id_po", group.Key);
            newRow.SetField("Status", maxPremRow.Field<string>("Status"));
            newRow.SetField("Cost_ex", group.Sum(r => r.Field<double?>("Cost_ex")));

            newRow.SetField("Name", maxPremRow.Field<string>("Name"));
            newRow.SetField("Salary", group.Sum(r => r.Field<double?>("Cost_ex")));
            newRow.SetField("Description", maxPremRow.Field<string>("Description"));
            newRow.SetField("Date", maxPremRow.Field<string>("Date"));


        }