Question

In C#/ASP.NET 3.5, I have a DataTable which pulls rows from the database. I want to dynamically apply a sort filter to the datatable (could be a dataview), and then do a loop through the ‘rows’ of the sorted data to use each row for some metrics.

I would greatly prefer not to hit the database each time to do custom sorting, but I’m not sure how to get a sorted datatable from an original datatable.

I’m sure I’m forgetting/missing something simple, but I do not recall how to do this!

I want to do this on the ‘sorted’ list. It is currently doing it on the bound list from my query.

            foreach (DataRow dr in dtTags.Rows)             {                 LinkButton lbTag = new LinkButton();                 lbTag.CssClass = 'UserTagNoHover';                 lbTag.ID = 'hlUserTag' + dr['UserTagRID'].ToString();                 lbTag.Text = dr['Name'].ToString();                 //lbTag.Click += new System.EventHandler(this.Tag_OnClick);                 lbTag.CommandName = 'User_Click';                 lbTag.CommandArgument = 'hlUserTag' + dr['UserTagRID'].ToString();                 lbTag.ToolTip = 'Total uses: ' + dr['TotalCount'].ToString();                  Boolean bAlreadyExists = false;                 foreach (LinkButton lbTest in pnlTags.Controls)                 {                     if (lbTest.ID == lbTag.ID)                     {                         bAlreadyExists = true;                     }                 }                 if (bAlreadyExists == false)                 {                     pnlTags.Controls.Add(lbTag);                 }             } 

Answer 1

The DataTable.Select() function does exactly what you seem to be wanting. Its second String parameter is a sorting string whose syntax is the same as SQL’s: [Column Name] ASC, [Other column name] DESC, etc.