How to convert LINQ result to DATATABLE?

Question

Is there a way to convert the result of a LINQ expression to a DataTable without going through each element?

Answer 1

There is no way to create it without stepping through each element. The Linq expression is computed as needed, so it will go through each line (for matching and selection).

I think you should try instead of DataTable.Select() ( MSDN link ), since it returns an array of DataRow objects that you can add the following to a new table:

 var rows = [ORIGINAL DATA TABLE].Select("id>5"); var dtb=[ORIGINAL DATA TABLE].Clone(); foreach(DataRow r in rows) { var newRow = dtb.NewRow(); newRow.ItemArray = r.ItemArray; dtb.Rows.Add(newRow);//I'm doubtful if you need to call this or not } 

Answer 2

Credit for this blogger , but I improved his algorithm here. Make yourself an extension method:

  public static DataTable ToADOTable<T>(this IEnumerable<T> varlist) { DataTable dtReturn = new DataTable(); // Use reflection to get property names, to create table // column names PropertyInfo[] oProps = typeof(T).GetProperties(); foreach (PropertyInfo pi in oProps) { Type colType = pi.PropertyType; if ((colType.IsGenericType) && (colType.GetGenericTypeDefinition() == typeof(Nullable<>))) colType = colType.GetGenericArguments()[0]; dtReturn.Columns.Add(new DataColumn(pi.Name, colType)); } foreach (T rec in varlist) { DataRow dr = dtReturn.NewRow(); foreach (PropertyInfo pi in oProps) dr[pi.Name] = pi.GetValue(rec, null) == null ? DBNull.Value : pi.GetValue(rec, null); dtReturn.Rows.Add(dr); } return (dtReturn); } 

Using:

 DataTable dt = query.ToADOTable();