标签: linq-to-dataset

我想编写一个函数"getCount"来为数据表中的不同用户名返回int的结果,如下所示:

static void Main(string[] args)
{
    DataTable table = new DataTable();
    table.Columns.Add("username", typeof(string));
    table.Columns.Add("count", typeof(int));
    table.Columns.Add("code", typeof(string));
    table.Rows.Add("Peter", 300, "wer");      
    table.Rows.Add("Peter", 299, "sdf");
    table.Rows.Add("Peter", 298, "34d");
    table.Rows.Add("Peter", 297, "4ed");
    table.Rows.Add("Paul", 200, "1vc");
    table.Rows.Add("Paul", 200, "64f");
    table.Rows.Add("Paul", 200, "45d");
    table.Rows.Add("Paul", 200, "dcd");

    //expectedly 300, i.e. the first row of count column for peter
    int x1 = getCount(table, "Peter");   

    //expectedly 200, i.e. the first row of count column for paul
    int x2 = getCount(table, "Paul");   
}

static int getCount(DataTable dt, string name) …

我有一个带有动态列列的数据表,并希望聚合基于数字的列并将最终行保存到新的数据表中.

DataTable示例: -

PartnerName   CreditCol  DebitCol  AmountCol ....
P1              10       20        30 
P2              1        2         3 
P3              3        1         10
P2              1        100       200

所需的输出应为: -

PartnerName   CreditCol  DebitCol  AmountCol ....
P1              10       20        30 
P2              2        102       203 
P3              3        1         10

这里的主要内容是列集,并且是动态的.有时,可能有两列,有时可能是20列.请建议linq查询或任何其他解决方案.

我有一个简单的数据表,有四列和一些数据行:

DataTable results = new DataTable();
results.Columns.Add("Wellbore", typeof(string));
results.Columns.Add("Date", typeof(DateTime));
results.Columns.Add("WB", typeof(string));
results.Columns.Add("factor", typeof(double));

当"date = 1/1/2017"时,我使用Linq查询获取"数据行列表":

var AllRowsAtPlanningDate = results.AsEnumerable()
   .Where(x => ((x.Field<DateTime>("Date") == PlanningDate))).ToList();

我想在" "列中获得"不同"值.我只想要而不是再次.wellboreAllRowsAtPlanningDateList<string>list<datarows>

怎么做？我一直在检查一些例子,但无济于事.

我有一个像这样的数据表

ProductId CountThisWeek CountLastWeek
        1            10            15         
        1            20             5

        2             5            10
        2            10            15
        2            10            20

        3            10            15

我需要通过“压缩”（按 productId 求和）我的初始数据表来获得一个新的数据表，如下所示：

ProductId CountThisWeek CountLastWeek
        1            30            20         
        2            25            45
        3            10            15

有没有办法使用 LINQ 或其他技术来做到这一点（.NET 3.5）？

I have a c# code as below, Its showing error at IEnumerable<\u003C\u003Ef__AnonymousType0 Can someone tell me how to solve it.

dataSet = this.GetData.getInfo("SELECT b.nBatchID, td.F_Name &' '& td.M_Name &' '& td.L_Name AS StaffName, b.BatchName FROM (Batch AS b LEFT JOIN BatchTrainer AS bt ON b.nBatchID = bt.nBatchId) LEFT JOIN TrainerDetails AS td ON bt.TrainerId = td.TrainerID", "Batch");
            IEnumerable<\u003C\u003Ef__AnonymousType0<object, string, string>> datas = dataSet.Tables[0].Copy().AsEnumerable().GroupBy<DataRow, object>((Func<DataRow, object>) (row => row["nBatchId"])).Select(g =>
            {
              var data = new{ id = g.Key, text = string.Join(",", …