.net - 如何将 CsvHelper 记录添加到 DataTable 以用于 SqlBulkCopy 到数据库

Question

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，在向数据表添加行时出现异常。异常(exception)情况是:“无法将‘MvcStockAnalysis.Models.StockPrice’类型的对象转换为‘System.IConvertible’类型。无法存储在日期列中。预期类型为 DateTime。”

示例 CSV 文件来自雅虎财经。例如: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 header : 日期 开盘价 最高价 最低价 收盘量 调整收盘价

我正在将 CSV 文件读入的模型:

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:

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");
    }
}

尝试将 CsvHelper 记录添加到 DataTable 的代码如下:

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 以用于 SqlBulkCopy 到数据库？

Answer 1

如果我没记错的话，你应该能够用更少的代码来完成它。在进入 DataTable 之前，您也不必将其放入另一个类中。

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 );
}