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c# - 如何在sqlbulkcopy中设置自动映射

转载 作者:太空狗 更新时间:2023-10-30 01:05:10 28 4
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在我们的项目中我们使用的是Linq2SQL,但是现在我们需要有一个可能性来快速地向数据库表中插入近15k行,所以我写了一个扩展方法:

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。当我取消注释 ColumnMappings 行时,这段代码效果很好,但它们不适合,因为如果有人更改 dbml,这段代码将无法工作(这段代码不灵活 :))。 ToDataTable() 是一种基于反射的方法,它将维护列表转换为数据表。

如有任何帮助,我将不胜感激

最佳答案

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 取消 DataTable :

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);
}
}
}

关于c# - 如何在sqlbulkcopy中设置自动映射,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/20045285/

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