在我们的项目中,我们使用linq2sql,但是现在我们需要有一个可能在数据库表中快速插入近15k行,所以我编写了一个扩展方法:
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);
}
}
maintanance是自动生成的linq2sql类。当我取消对columnmappings行的注释时,这段代码工作得很好,但它们不适合,因为如果有人更改dbml,这段代码就不会工作(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。我很感激你的帮助
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);
}
}
或者更好:通过FastMember消除
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);
}
}
}