Need to compare two table values and save the difference of both tables using asp.net c#

selvi subramanian

14y12.7k.NET

need to compare two table values and save the difference of both tables using asp.net c#

2 Replies

Know the answer? Post it — somebody with the same question will find it here.

Amit Mohanty7y ago
1. Try This...
2. public DataTable getDiffRecords(DataTable dtDataOne, DataTable dtDataTwo)
3. {
4. DataTable returnTable = new DataTable("returnTable");
6. using (DataSet ds = new DataSet())
7. {
8. ds.Tables.AddRange(new DataTable[] { dtDataOne.Copy(), dtDataTwo.Copy() });
10. DataColumn[] firstColumns = new DataColumn[ds.Tables[0].Columns.Count];
11. for (int i = 0; i < firstColumns.Length; i++)
12. {
13. firstColumns[i] = ds.Tables[0].Columns[i];
14. }
16. DataColumn[] secondColumns = new DataColumn[ds.Tables[1].Columns.Count];
17. for (int i = 0; i < secondColumns.Length; i++)
18. {
19. secondColumns[i] = ds.Tables[1].Columns[i];
20. }
22. DataRelation r1 = new DataRelation(string.Empty, firstColumns, secondColumns, false);
23. ds.Relations.Add(r1);
25. DataRelation r2 = new DataRelation(string.Empty, secondColumns, firstColumns, false);
26. ds.Relations.Add(r2);
28. for (int i = 0; i < dtDataOne.Columns.Count; i++)
29. {
30. returnTable.Columns.Add(dtDataOne.Columns[i].ColumnName, dtDataOne.Columns[i].DataType);
31. }
33. returnTable.BeginLoadData();
34. foreach (DataRow parentrow in ds.Tables[0].Rows)
35. {
36. DataRow[] childrows = parentrow.GetChildRows(r1);
37. if (childrows == null || childrows.Length == 0)
38. returnTable.LoadDataRow(parentrow.ItemArray, true);
39. }
41. foreach (DataRow parentrow in ds.Tables[1].Rows)
42. {
43. DataRow[] childrows = parentrow.GetChildRows(r2);
44. if (childrows == null || childrows.Length == 0)
45. returnTable.LoadDataRow(parentrow.ItemArray, true);
46. }
47. returnTable.EndLoadData();
48. }
49. return returnTable;
50. }

Senthilkumar14y ago

Hi Selvi,

Hi,

If you have two data tables then

public static DataTable CompareTwoDataTable(DataTable dt1, DataTable dt2)

{

dt1.Merge(dt2);

DataTable d3 = dt2.GetChanges();

return d3;

}

Another way of doing is iterate the datatable and check the each row. If there is any difference then add it into another datatable.

//create two dataTables with the same columns

DataTable table1 = new DataTable();

DataTable table2 = new DataTable();

table1.Columns.Add(new DataColumn("name", typeof(string)));

table1.Columns.Add(new DataColumn("age", typeof(int)));

table1.Columns.Add(new DataColumn("born", typeof(DateTime)));

//same you do for table2!

//then fill them up

//create the third table - a clone of table1

DataTable table3 = table1.Clone();

bool found = true;

bool notFound = false;

foreach (DataRow row1 in table1.Rows)

{

found = false;

notFound = false;

foreach (DataRow row2 in table2.Rows)

{

string item1 = row1[0].ToString();

string item2 = row2[0].ToString();

if (item1 != item2)

{

found = true;

}

else if (item1 == item2)

{

notFound = true;

}

if (found == true && notFound == false)

{

DataRow row3 = table3.NewRow();

row3["name"] = row1[0];

row3["age"] = row1[1];

row3["born"] = row1[2];

table3.Rows.Add(row3);

}

For more info:

http://social.msdn.microsoft.com/Forums/en/csharpgeneral/thread/1407a809-9551-4646-b74d-3dee3535249c

http://www.dotnetperls.com/datatable-compare-rows