如何在sqlbulkcopy中设置自动映射 [英] how to set up auto mapping in sqlbulkcopy

问题描述

在我们的项目中，我们使用Linq2SQL，但是现在我们需要有可能在数据库表中快速插入近15,000行，所以我写了一个扩展方法:

In our project we use Linq2SQL, but now we need to have a possibility to quickly insert nearly 15k rows in database table, so i wrote an extension method:

public static void BulkInsertBigData(Table<Maintenance> maintenance, IEnumerable<Maintenance> maintenancesToInsert)
    {

            using (var copy = new SqlBulkCopy(maintenance.Context.Connection.ConnectionString, SqlBulkCopyOptions.KeepIdentity | SqlBulkCopyOptions.KeepNulls))
            {
                //copy.ColumnMappings.Add("Id", "Id");
                //copy.ColumnMappings.Add("FacilityId", "FacilityId");
                //copy.ColumnMappings.Add("ParentFacilityId", "ParentFacilityId");
                //copy.ColumnMappings.Add("StartTime", "StartTime");
                //copy.ColumnMappings.Add("EndTime", "EndTime");
                //copy.ColumnMappings.Add("ExpirationTime", "ExpirationTime");
                //copy.ColumnMappings.Add("DispatcherUserName", "DispatcherUserName");
                copy.DestinationTableName = "dbo.Maintenance";
                var data = maintenancesToInsert.ToDataTable();
                copy.WriteToServer(data);
            }

    }

维护是自动生成的Linq2SQL类.当我取消对ColumnMappings行的注释时，此代码很好用，但是它们不合适，因为如果有人更改dbml，则此代码将不起作用(此代码不敏捷:)). ToDataTable()是一种基于反射的方法，它将维护列表转换为数据表.

Maintanance is auto-generated Linq2SQL class. This code works great when i uncomment ColumnMappings lines, but they doesn't fit, because if somebody will change dbml this code won't work(this code isn't agile :) ). ToDataTable() is a reflection-based method, which converts List of Maintenance to DataTable.

如果有任何帮助，我将不胜感激

I'll be gratefull for any help

推荐答案

怎么样:

public static void BulkInsertBigData<T>(Table<T> definition, IEnumerable<T> rows)
{
    using (var copy = new SqlBulkCopy(definition.Context.Connection.ConnectionString, SqlBulkCopyOptions.KeepIdentity | SqlBulkCopyOptions.KeepNulls))
    {
        var meta = definition.Context.Mapping.GetMetaType(typeof(T));
        foreach (var col in meta.DataMembers)
        {
            copy.ColumnMappings.Add(col.Member.Name, col.MappedName);
        }
        copy.DestinationTableName = meta.Table.TableName;
        var data = rows.ToDataTable();
        copy.WriteToServer(data);
    }
}

甚至更好:通过 FastMember :

public static void BulkInsertBigData<T>(Table<T> definition, IEnumerable<T> rows)
{
    using (var copy = new SqlBulkCopy(definition.Context.Connection.ConnectionString, SqlBulkCopyOptions.KeepIdentity | SqlBulkCopyOptions.KeepNulls))
    {
        var meta = definition.Context.Mapping.GetMetaType(typeof(T));
        var members = new List<string>(meta.DataMembers.Count);
        foreach (var col in meta.DataMembers)
        {
            copy.ColumnMappings.Add(col.Member.Name, col.MappedName);
            members.Add(col.Member.Name);
        }
        copy.DestinationTableName = meta.Table.TableName;
        using (var reader = ObjectReader.Create(rows, members.ToArray()))
        {
            copy.WriteToServer(reader);
        }
    }
}

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