How to add a text file in to existing datatable as a new column

Question

I have to add a data column in to the existing data table.

I need to add one more column and data to that table from a .txt file in to 0th column and from second column i need to keep the DB data. I am not using any grid view and stream reader to my app.Need to use File.ReadAllLines();

my .txt file is like

NAME
val1
val3
val5

I have written a code that will add data to the first column row but after addedd my pgm suddenly stoped.Its not returning my table after this .Some issue with the loop i think.I am not sure.. please help me on this

My code..

   adapter.Fill(table);//some db data clms inside the table

 if (tablename == "TestData")
  {
var pathC = @"H:\claimdetails\claims\names.txt";

string[] result = File.ReadAllLines(pathC);

  DataColumn Col = table.Columns.Add("Name", typeof(String));

  Col.SetOrdinal(0); // set column to first position

      i=1;
    foreach (DataRow row in table.Rows)
     {
      row["Name"] = result[i];
      i++;
      }

    }
 return table; // not coming here

After this foreach suddenly program stops and not returning the table

Answer 1

Hi @RAMAN RAGAVAN ,

Thank you for the ask.

I think you just need a if condition to check the array length + start the index from 0 instead of 1. Please see the code below. Thanks!

            var pathC = @"H:\claimdetails\claims\names.txt";  
            string[] result = File.ReadAllLines(pathC);  
            DataColumn Col = table.Columns.Add("Name", typeof(String));  
            Col.SetOrdinal(0); // set column to first position  
            i = 0;  
            foreach (DataRow row in table.Rows)  
            {  
                if (i < result.Length)  
                {  
                    row["Name"] = result[i];  
                    i++;  
                }  
            }

Answer 2

@RAMAN RAGAVAN ,

I have one doubt and this problem occured.What if the table row count is less and Name colom count is big?

If you worry about the Name column has a big count and table row count is less than the Name row count, I suggest that you can add some empty row by comparing the row count.

Here is a code example you could refer to.

  static void Main(string[] args)  
        {  
            DataTable table = new DataTable();  
            table.TableName="test1";  
            table.Columns.Add("Age", typeof(int));  
            table.Columns.Add("Id", typeof(int));  
            table.Rows.Add(23,1001);  
            table.Rows.Add(24, 1002);  
            table.Rows.Add(25, 1003);  
            if(table.TableName=="test1")  
            {  
                string[] str = File.ReadAllLines("D:\\1.txt");  
                table.Columns.Add(str[0],typeof(string)).SetOrdinal(1);  
  
                int count = str.Count()-1-table.Rows.Count;  
                if(count>0)  
                {  
                    for (int i = 0; i < count; i++)  
                    {  
                        table.Rows.Add();  
                    }  
                     
                }  
                for (int i = 0; i < table.Rows.Count; i++)  
                {  
                      
                    table.Rows[i][str[0]]=str[i+1];  
                }  
  
                Console.WriteLine("success");  
            }  
                  
  
              
  
        }  

Result:

As we can see from the following link, we can see the Name column row's count is more than the initial Datatable row's count.

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