Question

Let T1 and T2 are DataTables with following fields

T1(CustID, ColX, ColY)  T2(CustID, ColZ) 

I need the joint table

TJ (CustID, ColX, ColY, ColZ) 

How this can be done in C# code in a simple way? Thanks.

Answer 1

If you are allowed to use LINQ, take a look at the following example. It creates two DataTables with integer columns, fills them with some records, join them using LINQ query and outputs them to Console.

    DataTable dt1 = new DataTable();     dt1.Columns.Add('CustID', typeof(int));     dt1.Columns.Add('ColX', typeof(int));     dt1.Columns.Add('ColY', typeof(int));      DataTable dt2 = new DataTable();     dt2.Columns.Add('CustID', typeof(int));     dt2.Columns.Add('ColZ', typeof(int));      for (int i = 1; i <= 5; i++)     {         DataRow row = dt1.NewRow();         row['CustID'] = i;         row['ColX'] = 10 + i;         row['ColY'] = 20 + i;         dt1.Rows.Add(row);          row = dt2.NewRow();         row['CustID'] = i;         row['ColZ'] = 30 + i;         dt2.Rows.Add(row);     }      var results = from table1 in dt1.AsEnumerable()                  join table2 in dt2.AsEnumerable() on (int)table1['CustID'] equals (int)table2['CustID']                  select new                  {                      CustID = (int)table1['CustID'],                      ColX = (int)table1['ColX'],                      ColY = (int)table1['ColY'],                      ColZ = (int)table2['ColZ']                  };     foreach (var item in results)     {         Console.WriteLine(String.Format('ID = {0}, ColX = {1}, ColY = {2}, ColZ = {3}', item.CustID, item.ColX, item.ColY, item.ColZ));     }     Console.ReadLine();  // Output: // ID = 1, ColX = 11, ColY = 21, ColZ = 31 // ID = 2, ColX = 12, ColY = 22, ColZ = 32 // ID = 3, ColX = 13, ColY = 23, ColZ = 33 // ID = 4, ColX = 14, ColY = 24, ColZ = 34 // ID = 5, ColX = 15, ColY = 25, ColZ = 35