Question

在我们的项目中我们使用Linq2SQL，但现在我们需要有可能在数据库表中快速插入近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);
            }

    }

Maintanance是自动生成的Linq2SQL类。当我取消注释ColumnMappings行时，这段代码很有用，但是它们不合适，因为如果有人将更改dbml，这段代码将无效（此代码不灵活:)）。 ToDataTable()是一种基于反射的方法，可将维护列表转换为DataTable。

我会感激任何帮助

Answer 1

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);
        }
    }
}

如何在sqlbulkcopy中设置自动映射

1 个答案: