如何将CsvHelper记录添加到DataTable以用于SqlBulkCopy到数据库 [英] How to add CsvHelper records to DataTable to use for SqlBulkCopy to the database
问题描述
我正在尝试使用CsvHelper读取CSV文件，将每条记录加载到DataTable中，然后使用SqlBulkCopy将数据插入数据库表中.使用当前代码，将一行添加到DataTable时出现异常.例外是:无法将类型为'MvcStockAnalysis.Models.StockPrice'的对象强制转换为类型为'System.IConvertible'.无法存储在Date列中.预期的类型为DateTime."
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
CSV文件包含以下标题: 日期开盘高低开盘成交量调整
The CSV file contains the following header: Date Open High Low Close Volume Adj Close
我将CSV文件读取到的模型:
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; }
}
}
CSV文件到StockPrice类的映射使用以下内容:
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");
}
}
试图将CsvHelper记录添加到DataTable的代码如下:
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);
}
如何将CsvHelper记录添加到DataTable中以用于SqlBulkCopy到数据库?
How can I add CsvHelper records to DataTable to use for SqlBulkCopy to the database?
推荐答案
我能够通过添加DataTable行并将其显式填充来实现此目的，而不必尝试将CsvHelper记录添加为一行.
I was able to get this to work by adding a DataTable row and filling it in explicitly, instead of trying to add a CsvHelper record as a row.
我用以下部分代替了上面显示的类似部分:
I used the following part instead of the similar part that is shown above:
foreach (var record in records)
{
DataRow row = dt.NewRow();
record.CompanyId = company.Id;
row["Date"] = record.Date;
row["Close"] = record.Close;
row["AdjClose"] = record.AdjClose;
row["High"] = record.High;
row["Low"] = record.Low;
row["Open"] = record.Open;
row["Volume"] = record.Volume;
row["CompanyId"] = record.CompanyId;
dt.Rows.Add(row);
}
如果您无需花费太多精力就能解决问题，我将接受您的回答作为答案.
If you can solve the issue without so much hard coding, I will accept your answer as the answer.
这篇关于如何将CsvHelper记录添加到DataTable以用于SqlBulkCopy到数据库的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
