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Convert datareader to CSV and export to web browser in ASP.NET C#

I have a datareader

while (thisReader.Read())
{
}

Now how can I export the contents of this datarader to a web browser in CSV format, so the user can save the file on this desktop.

0
mugsey
Asked:
mugsey
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1 Solution
 
Pratima PharandeCommented:
Try this
 //Add Response header 
        Response.Clear();
        Response.AddHeader("content-disposition", string.Format("attachment;filename={0}.csv", fileName));
        Response.Charset = "";
        Response.ContentType = "application/vnd.xls";
        //GET Data From Database                
        SqlConnection cn = new SqlConnection(dataSrc.ConnectionString);
        string query = dataSrc.SelectCommand.Replace("\r\n", " ").Replace("\t", " ");
        
        SqlCommand cmd = new SqlCommand(query, cn);
        
        cmd.CommandTimeout = 999999 ;
        cmd.CommandType    = CommandType.Text;
        try
        {
            cn.Open();
            SqlDataReader dr = cmd.ExecuteReader();
            StringBuilder sb = new StringBuilder();            
            //Add Header          
            for (int count = 0; count < dr.FieldCount; count++)
            {
                if (dr.GetName(count) != null)
                    sb.Append(dr.GetName(count));
                if (count < dr.FieldCount - 1)
                {
                    sb.Append(",");
                }
            }
            Response.Write(sb.ToString() + "\n");
            Response.Flush();            
            //Append Data
            while (dr.Read())
            {
                sb = new StringBuilder();
               
                for (int col = 0; col < dr.FieldCount - 1; col++)
                {
                    if (!dr.IsDBNull(col))
                        sb.Append(dr.GetValue(col).ToString().Replace(",", " "));
                    sb.Append(",");
                }
                if (!dr.IsDBNull(dr.FieldCount - 1))
                    sb.Append(dr.GetValue(dr.FieldCount - 1).ToString().Replace(",", " "));
                Response.Write(sb.ToString() + "\n");
                Response.Flush();
            }
            dr.Dispose();

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Pratima PharandeCommented:
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bungHocCommented:
Try this:

private string ToCSV(DataTable dataTable)
{
 
  DataTable schemaTable = myReader.GetSchemaTable();
 
  StringBuilder sb = new StringBuilder();      
  foreach (DataColumn column in schemaTable.Columns)
  {
    sb.Append(column.ColumnName + ',');
  }            
 
  sb.Append("\r\n");
      
  foreach (DataRow row in schemaTable.Rows)
  {
    foreach (DataColumn column in schemaTable.Columns)
    {
      sb.Append(row[column].ToString() + ',');
    }                  
    sb.Append("\r\n");
  }      
  return sb.ToString();
}

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mugseyAuthor Commented:
OK thanks guys I will try in the next hour
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mugseyAuthor Commented:
Thanks pratima_mcs

How can I specify the file name and where to save the file?  Thanks
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Pratima PharandeCommented:
When you run this code it will ask with a popup to open , save
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mugseyAuthor Commented:
OK thanks - so you know the line

Response.AddHeader("content-disposition", string.Format("attachment;filename={0}.csv", fileName));

Where does filename come from?

You see my code is like this

Currently I have a datareader that is populated from a dynamic search

  while (thisReader.Read())
                {
                 

                }

How can I amend your code above so it works



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Pratima PharandeCommented:
Response.AddHeader("content-disposition", string.Format("attachment;filename={0}.csv", fileName));

in this they have used the parament send to the function ...

you can use your own tempory file name there like

Response.AddHeader("content-disposition", string.Format("attachment;filename=temp.csv", fileName));

that will appear by default in save dialog
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mugseyAuthor Commented:
OK thANKS

But could you amend your example so it wiould fit into the following?

while (thisReader.Read())
                {
                 

                }



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Pratima PharandeCommented:

//Add Response header 
        Response.Clear();
        Response.AddHeader("content-disposition", string.Format("attachment;filename={0}.csv", fileName));
        Response.Charset = "";
        Response.ContentType = "application/vnd.xls";
       
                
            StringBuilder sb = new StringBuilder();            
            //Add Header   Put this if you want headers        
            for (int count = 0; count < thisReader.FieldCount; count++)
            {
                if (thisReader.GetName(count) != null)
                    sb.Append(thisReader.GetName(count));
                if (count < thisReader.FieldCount - 1)
                {
                    sb.Append(",");
                }
            }
            Response.Write(sb.ToString() + "\n");
            Response.Flush();            
            //Append Data
            while (thisReader.Read())
            {
                sb = new StringBuilder();
               
                for (int col = 0; col < thisReader.FieldCount - 1; col++)
                {
                    if (!thisReader.IsDBNull(col))
                        sb.Append(thisReader.GetValue(col).ToString().Replace(",", " "));
                    sb.Append(",");
                }
                if (!thisReader.IsDBNull(thisReader.FieldCount - 1))
                    sb.Append(thisReader.GetValue(thisReader.FieldCount - 1).ToString().Replace(",", " "));
                Response.Write(sb.ToString() + "\n");
                Response.Flush();
            }
            thisReader.Dispose();

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