如何返回动态类型List< dynamic>与Dapper ORM [英] How to return dynamic types List<dynamic> with Dapper ORM

问题描述

我已经使用Dapper.net已有一段时间了，它是一个非常好的ORM映射器，可以很好地与.Net动态类型一起使用.

I have been using Dapper.net for a while now and its a very good ORM mapper which works great with .Net dynamic types.

但是我注意到，当Dapper从数据库中检索数据时，它以DapperRow类型返回.

But I noticed that when Dapper retrieves data from a database it returns as DapperRow type.

是否可以通过其他任何方式(如System.Dynamic.ExpandoObject)将其返回?

Is there are any way that I can return it in any other type Like System.Dynamic.ExpandoObject?

推荐答案

DapperRow对象旨在在行之间共享很多状态.例如，如果您获取40行，则列名称等仅一次存储.如果我们使用ExpandoObject，则需要按行进行配置.因此，使用DapperRow作为幕后实现细节是故意的.

The DapperRow object is designed to share a lot of state between rows. For example, if you fetch 40 rows, the column names etc are only stored once. If we used ExpandoObject, this would need to be configured per row. Hence, the use of DapperRow as the behind-the-scenes implementation detail is a deliberate efficiency thing.

请注意，从dynamic API返回的对象也可以转换为IDictionary<string,object>.

Note that the object returned from the dynamic APIs can also be cast as IDictionary<string,object>.

但是，我愿意支持支持该词典用法的 other 类型-其中ExpandoObject是其中之一.是的，它可以 进行更改，使得:

I would, however, be open to supporting other types that support this dictionary usage - of which ExpandoObject is one. So yes, it could be changed such that:

var rows = conn.Query<ExpandoObject>(...);

有效.它只需要代码 support 即可，并且该代码目前不存在.因此，不，但也许会在将来的版本中."

works. It simply requires code to support it, and that code does not currently exist. So "no, but perhaps in a future build".

还请注意，您根本不需要使用DapperRow.预期的更多方案是使用通用API来实现您自己的类型.

Note also that you don't need to use DapperRow at all... The more expected scenario is to use the generic API to materialize your own types.

这篇关于如何返回动态类型List< dynamic>与Dapper ORM的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！