Sorting data table by multiple columns using C#

Question

I have a Datatable with columns named foldername,documentname. Data as below:

FolderName  DocumentName
Folder1     HR[D] Document
Folder1     ___----'
Folder1     Asp_example.pdf
Folder2     SD
Folder3     Heavy_weight
Folder3     Accesorial Services

How to alphabetically sort DocumentName based on FolderName in .Net Framework 2.0.

Solution we tried is below but takes too many time as it contains more than 1200000 records.

int counter=0;

while (counter < searchDT.Rows.Count){
   string FolderName = Convert.ToString(searchDT.Rows[counter]["Folder Name"]);

   string exp = "[Folder Name] like '" + FolderName + "'";

   if (FolderName.Contains("%") || FolderName.Contains("_") || FolderName.Contains("[]") ||      FolderName.Contains("'"))

      exp = "[Folder Name] like '" + EscapeLikeValue(FolderName) + "'";

   string sortExpression = "[Document Name] ASC";

   DataRow[] drfoldername = searchDT.Select(exp, sortExpression);

   foreach (DataRow row in drfoldername)
     drfoldernameDT.ImportRow(row);

   counter += drfoldername.Length;

 }

Solution 1

DataTable dt = new DataTable();

DataView dv = new DataView(dt);
dv.Sort = "FolderName, DocumentName ASC";

Try that out. It will sort first for FolderName, then DocumentName.

If you need to send that to a component on the screen, you can do the same as you're doing with a DataTable.

Solution 2

Here was my solution to this problem:

Datatable FI = new Datatable();
DataView viewFI = new DataView(FI);
viewFI.Sort = "ServiceDate, ServiceRoute";
DataTable OFI= viewFI.ToTable();

Solution 3

Have you tried DataView.Sort?

dt.DefaultView.RowFilter = "FolderName , DocumentName ASC";
dt = dt.DefaultView.ToTable();

Comments

[user1931665]

Thanks a lot, it worked. For a simple line of coding, i wrote a hell of stupid code

[André Silva]

Don't forget to upvote and mark as correct answer. That estimulates us to help more and more.

[Neel]

stange this ans is useful for OP bt still havnt marked as asnwer

[André Silva]

Yeah. I get a bit sad when this happens, but at least I know that it helped OP.

[Admin]

@AndréSilva your solution is sorting only those columns which are of string type, suppose i have a column say colA which is having string values like 1.23, 11.34, and 2.34. Then it will sort it as 1.23, 11.34, 2.34 which is wrong.

[André Silva]

@PranayDeep SaQiB managed to answer that in another post. Basically you need to duplicate the DataTable and change the column you have into the type you need in order to sort it. Take a look at his answer: stackoverflow.com/questions/7572685/…

[Greg Trevellick]

Thanks - this is the only answer that worked for me. The key was having DataTable OFI= viewFI.ToTable(); which most other answers omitted.