how to export records in multiple csv files?

Question

i am trying to import multiple csv files from a folder using textfieldparser . each csv file contains header and 1 record , but when my import method runs it gives error of "a column named "PTNAME" is already belongs to datatable". i couldnt find the way where to change code . plz help me .

here is my import method,

public void ImportAllFilesOfFolder()
{
try
{ 
DataTable dt = new DataTable();
string sourceDir = txtsend.Text;
var Icsv = Directory.EnumerateFiles(sourceDir, "*.csv");

foreach (string currentfile in Icsv)
{
using (TextFieldParser parser = new TextFieldParser(currentfile))
{
parser.TextFieldType = FieldType.Delimited;
parser.Delimiters = new string[] { "," };
parser.HasFieldsEnclosedInQuotes = true;

string[] columns = parser.ReadFields();

for (int i = 0; i < columns.Length; i++)
{
 dt.Columns.Add(columns[i], typeof(string));
 }

while (!parser.EndOfData)
{
string[] fields = parser.ReadFields();
DataRow newrow = dt.NewRow();

for (int i = 0; i < fields.Length; i++)
{
newrow[i] = fields[i];
}

dt.Rows.Add(newrow);
}
}
}
con.Open();
SqlBulkCopy bc = new SqlBulkCopy(con.ConnectionString,      SqlBulkCopyOptions.TableLock);
bc.DestinationTableName = "SaiRamH";
bc.BatchSize = dt.Rows.Count;
 bc.WriteToServer(dt);
bc.Close();
}
 catch (SystemException e) { MessageBox.Show(e.Message); }
finally { con.Close(); }
} 

and here is my file structure,

PTNAME,REGNO/ID,BLOOD GRP,WARD NAME,DOC NAME,XRAY,PATHO,MEDICATION,BLOOD  GIVEN
Mrs.BHAGWAT SUGHANDA RAGHUNTH,SH1401/00457,,GENERAL WARD (FEMALE),SHELKE     SAMEER,MRI LS SPINE-PID L3-4 L5S1 MRI BRAIN --- NAD,BSL (R), IV DICLOGESIC RR    DRIP 1-0-1 TAB FLEXURA D 1-0-1 TAB ARCOPAN D 1-0-1 TAB BIO D3 STRONG 0-1-0 TAB ALPRAX 0.5 MG 0-0-1 XYNOSURE GEL L/A 1-1-1 TAB NERVSHINE ER 75 0-1-0 CERVICAL TRACTION AND LUMBAR TRACT ALTER WITH IFT 1-0-1,NOT GIVEN.

Answer 1

Made simple change by adding new variable firstFile. See code below

        public void ImportAllFilesOfFolder()
        {
            try
            {
                DataTable dt = new DataTable();
                string sourceDir = txtsend.Text;
                var Icsv = Directory.EnumerateFiles(sourceDir, "*.csv");

                bool firstFile = true;
                foreach (string currentfile in Icsv)
                {
                    using (TextFieldParser parser = new TextFieldParser(currentfile))
                    {
                        parser.TextFieldType = FieldType.Delimited;
                        parser.Delimiters = new string[] { "," };
                        parser.HasFieldsEnclosedInQuotes = true;

                        string[] columns = parser.ReadFields();

                        if (firstFile == true)
                        {
                            for (int i = 0; i < columns.Length; i++)
                            {
                                dt.Columns.Add(columns[i], typeof(string));
                            }
                        }

                        while (!parser.EndOfData)
                        {
                            string[] fields = parser.ReadFields();
                            DataRow newrow = dt.NewRow();

                            for (int i = 0; i < fields.Length; i++)
                            {
                                newrow[i] = fields[i];
                            }

                            dt.Rows.Add(newrow);
                        }
                    }
                    firstFile = false;
                }
            }
            catch (Exception e)
            {
            }
        }​

Answer 2

The code is attempting to add new columns each iteration of the foreach loop. Adding a conditional before the loop will prevent the issue. In the code below we are checking to see if the datatable's column has been populated.

If (dt.Columns.Count == 0)
{
    for (int i = 0; i < columns.Length; i++)
    {
    dt.Columns.Add(columns[i], typeof(string));
    }
}