c# - SQlBulkCopy 来自数据源的 DateTime 类型的给定值无法转换为指定目标列的 int 类型

Question

我在尝试执行以下“城市”数据表的 SqlBulkInsert 时收到上述错误代码：

DataTable cityTable = new DataTable(City.TABLE_NAME);
cityTable.Columns.Add("id", typeof(int));
cityTable.Columns.Add("name", typeof(string));
cityTable.Columns.Add("ascii_name", typeof(string));
cityTable.Columns.Add("alternate_names", typeof(string));
cityTable.Columns.Add("latitude", typeof(double));
cityTable.Columns.Add("longitude", typeof(double));
cityTable.Columns.Add("feature_class", typeof(char));
cityTable.Columns.Add("feature_code", typeof(string));
cityTable.Columns.Add("country_code", typeof(string));
cityTable.Columns.Add("country_code2", typeof(string));
cityTable.Columns.Add("population", typeof(long));
cityTable.Columns.Add("elevation", typeof(int));
cityTable.Columns.Add("modification_date", typeof(DateTime));
cityTable.Columns.Add("admin1code", typeof(string));
cityTable.Columns.Add("admin2code", typeof(string));
cityTable.Columns.Add("admin3code", typeof(string));
cityTable.Columns.Add("admin4code", typeof(string));
cityTable.Columns.Add("gtopo30", typeof(int));
cityTable.Columns.Add("timezone_name", typeof(string));
cityTable.Columns.Add("version", typeof(Binary));

以下是将每个实体添加到 DataTable 的代码：

object id = EvaluateNullity(parsedCity.Id);
object name = EvaluateNullity(parsedCity.Name);
object asciiName = EvaluateNullity(parsedCity.AsciiName);
object alternateNames = EvaluateNullity(parsedCity.AlternateNames);
object latitude = EvaluateNullity(parsedCity.Latitude);
object longitude = EvaluateNullity(parsedCity.Longitude);
object featureClass = EvaluateNullity(parsedCity.FeatureClass);
object featureCode = EvaluateNullity(parsedCity.FeatureCode);
object countryCode = EvaluateNullity(parsedCity.CountryCode);
object countryCode2 = EvaluateNullity(parsedCity.CountryCode2);
object population = EvaluateNullity(parsedCity.Population);
object elevation = EvaluateNullity(parsedCity.Elevation);
object modificationDate = EvaluateNullity(parsedCity.ModificationDate);
object admin1Code = EvaluateNullity(parsedCity.Admin1Code);
object admin2Code = EvaluateNullity(parsedCity.Admin2Code);
object admin3Code = EvaluateNullity(parsedCity.Admin3Code);
object admin4Code = EvaluateNullity(parsedCity.Admin4Code);
object gtopo30 = EvaluateNullity(parsedCity.Gtopo30);
object timeZoneName = EvaluateNullity(parsedCity.TimeZoneName);
object version = EvaluateNullity(parsedCity.Version);

cityRow["id"] = id;
cityRow["name"] = name;
cityRow["ascii_name"] = asciiName;
cityRow["alternate_names"] = alternateNames;
cityRow["latitude"] = latitude;
cityRow["longitude"] = longitude;
cityRow["feature_class"] = featureClass;
cityRow["feature_code"] = featureCode;
cityRow["country_code"] = countryCode;
cityRow["country_code2"] = countryCode2;
cityRow["population"] = population;
cityRow["elevation"] = elevation;
cityRow["modification_date"] = modificationDate;
cityRow["admin1code"] = admin1Code;
cityRow["admin2code"] = admin2Code;
cityRow["admin3code"] = admin3Code;
cityRow["admin4code"] = admin4Code;
cityRow["gtopo30"] = gtopo30;
cityRow["timezone_name"] = timeZoneName;
cityRow["version"] = version;

以及 EvaluateNullity 的代码：

    public object EvaluateNullity(object entity)
    {
        return entity ?? DBNull.Value;
    }

我从这条错误消息中的理解是，A DateTime 值被放置在上述 int 列之一中。但是，稍后进行快速的条件调试，并在即时窗口中进行检查，发现所有 int 列中都没有放置 DateTime 类型。 http://desmond.imageshack.us/Himg42/scaled.php?server=42&filename=mod1rm.jpg&res=landing http://desmond.imageshack.us/Himg37/scaled.php?server=37&filename=modyf.jpg&res=landing

我真的很难过。

Answer 1

从大卫安德烈斯：

仔细检查 cityTable 中定义的列的顺序是否与数据库表本身中的列顺序匹配。

Answer 2

此错误的一个不明显原因是您必须有一个表示标识列的属性，即使您可以不设置它们。

Answer 3

对我来说，这是实体框架模型类和实际表之间的不匹配（忘记从 db 搭建表模型）：

//------------------------------------------------------------------------------
// <auto-generated>
//     This code was generated from a template.
//
//     Manual changes to this file may cause unexpected behavior in your application.
//     Manual changes to this file will be overwritten if the code is regenerated.
// </auto-generated>
//------------------------------------------------------------------------------

namespace Databases
{
    using System;
    using System.Collections.Generic;
    
    public partial class FooTable
    {
        public int Id { get; set; }
        public string Name { get; set; }
        // --> Missing the LastUpdated Column.
    }
}

桌子：