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);
        }
    }
}

10-07 19:42
查看更多