I am trying to read a CSV file with CsvHelper, load each record into a DataTable, and then use SqlBulkCopy to insert the data into a database table. With the current code, I get an exception when adding a row to the DataTable. The exception is: "Unable to cast object of type 'MvcStockAnalysis.Models.StockPrice' to type 'System.IConvertible'.Couldn't store in Date Column. Expected type is DateTime."
The example CSV file is from yahoo finance. For example: http://ichart.yahoo.com/table.csv?s=MMM&a=0&b=1&c=2010&d=0&e=17&f=2014&g=d&ignore=.csv
The CSV file contains the following header: Date Open High Low Close Volume Adj Close
The model that I am reading the CSV file into:
namespace MvcStockAnalysis.Models
{
using System;
using System.Collections.Generic;
public partial class StockPrice
{
public int Id { get; set; }
public System.DateTime Date { get; set; }
public int CompanyId { get; set; }
public double High { get; set; }
public double Low { get; set; }
public double Close { get; set; }
public double AdjClose { get; set; }
public double Open { get; set; }
public double Volume { get; set; }
public virtual Company Company { get; set; }
}
}
The mapping of the CSV file to the StockPrice class uses the following:
public class StockPriceClassMap : CsvClassMap<StockPrice>
{
public override void CreateMap()
{
Map(m => m.Date).Name("Date");
Map(m => m.Close).Name("Close");
Map(m => m.AdjClose).Name("Adj Close");
Map(m => m.High).Name("High");
Map(m => m.Low).Name("Low");
Map(m => m.Open).Name("Open");
Map(m => m.Volume).Name("Volume");
}
}
The code that tries to add the CsvHelper records to the DataTable is as follows:
var connectionstring = ConfigurationManager.ConnectionStrings["MvcStockAnalysis.Models.MvcStockAnalysisContext"];
var connection = new SqlConnection();
connection.ConnectionString = connectionstring.ToString();
var destinationTableName = "StockPrices";
var company = db.Company
.Where(c => c.Symbol == "MMM")
.FirstOrDefault();
try
{
string path = HttpContext.Server.MapPath("~/App_Data/" + company.Symbol + @".csv");
if (System.IO.File.Exists(path))
{
using (StreamReader sr = new StreamReader(path))
{
using (var csv = new CsvReader(sr))
{
DataTable dt = new DataTable("StockPrices");
csv.Configuration.HasHeaderRecord = true;
csv.Configuration.RegisterClassMap<StockPriceClassMap>();
dt.Columns.Add(new DataColumn("Date", typeof(DateTime)));
dt.Columns.Add(new DataColumn("Close", typeof(Double)));
dt.Columns.Add(new DataColumn("AdjClose", typeof(Double)));
dt.Columns.Add(new DataColumn("High", typeof(Double)));
dt.Columns.Add(new DataColumn("Low", typeof(Double)));
dt.Columns.Add(new DataColumn("Open", typeof(Double)));
dt.Columns.Add(new DataColumn("Volume", typeof(Double)));
dt.Columns.Add(new DataColumn("CompanyId", typeof(Double)));
var records = csv.GetRecords<StockPrice>().ToList();
foreach (var record in records)
{
record.CompanyId = company.Id;
dt.Rows.Add(record);
}
// add dt to the database
using (var bulkCopy = new SqlBulkCopy(connection.ConnectionString))
{
// DataTable column names match my SQL Column names, so I simply made this loop.
foreach (DataColumn col in dt.Columns)
{
bulkCopy.ColumnMappings.Add(col.ColumnName, col.ColumnName);
}
bulkCopy.DestinationTableName = destinationTableName;
bulkCopy.WriteToServer(dt);
}
}
}
}
connection.Close();
}
catch (Exception e)
{
Console.Write(e.Message);
}
How can I add CsvHelper records to DataTable to use for SqlBulkCopy to the database?
If I'm not mistaken, you should be able to do it with a lot less code. You don't have to put in into another class before going into the DataTable
either.
while( csv.Read() )
{
var row = dt.NewRow();
foreach( DataColumn column in dt.Columns )
{
row[column.ColumnName] = csv.GetField( column.DataType, column.ColumnName );
}
dt.Rows.Add( row );
}