Question

I have a flat file of a dataset with 100 rows and 2001 attributes like this:

att1,att2,att4,att5,att6,att7,att8,att9,att10,....,att2000,type
5,3,4,4,1,5,1,3,2,4,...,12,Agresti
4,4,2,0,1,0,2,0,0,0,...,22,bbresti
0,0,0,0,0,0,0,0,1,0,...,34,bbresti
0,0,0,1,0,0,0,1,1,1,...,45,Agresti
...
0,6,0,0,0,0,1,0,3.5,...,1,Agresti

And I would like to preprocess this data as

i,j,val
1,1,5
1,2,4
1,3,0
1,4,0
...
1,100,0
2,1,3
2,2,4
2,3,0
2,4,0
...
2,100,6
3,1,4
3,2,2
3,3,0
3,4,0
...
...
2000,100,1

So i get rid of the last column type, I kmow that in sql I would do something like:

CREATE TABLE matrix (Row int NOT NULL, Column int NOT NULL, Value <datatype> NOT NULL)

SELECT Row AS Column
       ,Column AS Row
       ,Value
FROM matrix

But as I would like to just import the table in SQL, but How does the code look like in c#

Answer 1

Here’s an idea of some C# that will take your input file and reformat you’re requesting. Then use the SqlBulkCopy class to push your data up into a table in SQLServer.

Hope it helps.

using System.IO;

namespace ConsoleApplication1
{
     class Program
     {
          static void Main(string[] args)
          {
                string[] parts;
                //string[] lines = System.IO.File.ReadAllLines(@"somefile.csv");
                string[] lines = new string[] { 
                     "a1,a2,a3,a4,type", 
                     "22,33,44,55,t1", 
                     "222,333,444,555,t2", 
                     "2222,3333,4444,5555,t3" };
                int lineno = 1;

                string path = @"c:\output.csv";
                using (TextWriter writer = File.CreateText(path))
                {
                     foreach (string line in lines)
                     {
                          if (lineno > 1)
                          {
                                parts = line.Split(',');
                                for (int a = 0; a < parts.Length - 1; a++)
                                     writer.WriteLine(lineno.ToString() + "," + (a+1).ToString() + "," + parts[a]);
                          }
                          lineno++;
                     }
                }
          }
     }
}