Dapper-dot-net“无列名” [英] Dapper-dot-net "no column name"

问题描述

我有一个可能如下所示的结果集：

I have a result set that might look like this:

ID    (no column name)  anotherID
----  ----------------  ----------
1        super            3
1        super            4
3        duper            6
4        really           7
4        really           8

我有2个问题：

第一：如何将dapper与没有名字的列一起使用？

First: How do I use dapper with a column with no name?

第二个：我想建立一个父子关系，这样我得到3个对象，每个对象都带有anotherID的列表，例如：

Second: I want to have a parent child relationship such that I get 3 objects each with a list of anotherID's for example:

public class MyObject
{
   public int ID
   public string Name
   public int[] Children
}

推荐答案

dapper不支持未命名的列。我从来没有真正看到它们的原因。

Well, un-named columns are not supported by dapper. I never really saw a reason for them.

我想我们可以为以下项目建立支持：

I guess we could build support for:

class Foo { [ColumnNumber(1)] public string Name {get;set;} }

问题在于它引入了一种非常脆弱的查询方法，我强烈不喜欢这种方法，将指令传递给 Query 同样笨拙。

The trouble is that it introduces a very fragile method of querying which I strongly dislike, passing a directive to Query is just as clunky.

但是，如果您乐于改变获取结果的方式，则可以解决此问题。

However, if you are happy to change the way you grab the results you could work around this.

var grid = QueryMultiple(@"set nocount on 
declare @t table(Id int, Name nvarchar(max), AnotherId int)

insert @t
exec proc

set nocount off 
select Id, Name from @t
select Id, AnotherId from @t
");

然后在此处使用该技术进行多重映射：使用Multi-Mapper创建对象层次结构

Then use the technique here to multi map: Multi-Mapper to create object hierarchy

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