无法按数据表分组

Question

我正在尝试按以下数据表分组：

+-------+---------+---------------------+---------+-----------+--------+----------+--------------+---------+-----------+---------+------------+
| ID_OR | TIPO_OR | ORA_OR              | SENT_OR | ID_OR_CFG | ID_ART | TIPO_ART | COD_ART      | QTA_ART | ID_OR_ART | COD_VAR | ID_ART_VAR |
+-------+---------+---------------------+---------+-----------+--------+----------+--------------+---------+-----------+---------+------------+
| 40    | MENU    | 10/06/2020 15:56:47 | 0       | 1         | 132    | PLUREP   | CAFFE        | 1       | 40        |         |            |
+-------+---------+---------------------+---------+-----------+--------+----------+--------------+---------+-----------+---------+------------+
| 40    | MENU    | 10/06/2020 15:56:47 | 0       | 1         | 133    | PLUREP   | REPARTO 0019 | 1       | 40        |         |            |
+-------+---------+---------------------+---------+-----------+--------+----------+--------------+---------+-----------+---------+------------+
| 40    | MENU    | 10/06/2020 15:56:47 | 0       | 1         | 134    | PLUREP   | REPARTO 0018 | 1       | 40        |         |            |
+-------+---------+---------------------+---------+-----------+--------+----------+--------------+---------+-----------+---------+------------+
| 40    | MENU    | 10/06/2020 15:56:47 | 0       | 1         | 135    | PLUREP   | REPARTO 0037 | 1       | 40        |         |            |
+-------+---------+---------------------+---------+-----------+--------+----------+--------------+---------+-----------+---------+------------+
| 40    | MENU    | 10/06/2020 15:56:47 | 0       | 1         | 136    | PLUREP   | CAFFE        | 1       | 40        | VAR0001 | 136        |
+-------+---------+---------------------+---------+-----------+--------+----------+--------------+---------+-----------+---------+------------+
| 40    | MENU    | 10/06/2020 15:56:47 | 0       | 1         | 136    | PLUREP   | CAFFE        | 1       | 40        | VAR0002 | 136        |
+-------+---------+---------------------+---------+-----------+--------+----------+--------------+---------+-----------+---------+------------+
| 40    | MENU    | 10/06/2020 15:56:47 | 0       | 1         | 136    | PLUREP   | CAFFE        | 1       | 40        | VAR0003 | 136        |
+-------+---------+---------------------+---------+-----------+--------+----------+--------------+---------+-----------+---------+------------+

datatable中的数据来自mysql，该表表示订单信息，物料和物料的变体，因此我试图建立一个包含其物料的订单清单，其中包含物料的变体。] >

首先，我需要按等于订单ID的ID_OR对数据表进行分组，因此我尝试执行以下var ordini = dt.AsEnumerable().GroupBy(r => r.Field<int>("ID_OR"));，但它没有任何效果，通过ordini进行的迭代无论如何都要遍历所有数据表行。 ..然后在ordini迭代中，我试图通过仍然按ID_ART将它们分组来迭代每个订单的项目，但是即使该group by也无效，并且只是在ID_ART 136中将项目添加了三倍，列表。

我用来建立订单列表的整个代码如下：

var ordini = dt.AsEnumerable().GroupBy(r => r.Field<int>("ID_OR"));
foreach(var ordine in ordini)

    int id_ordine = ordine.Key;
    foreach (DataRow ro in ordine)
    
        List<Ordine.Articoli> list_articoli = new List<Ordine.Articoli>();
        var articoli = dt.AsEnumerable().Where(r => r.Field<int>("ID_OR_ART") == id_ordine).GroupBy(r => r.Field<int>("ID_ART"));
        foreach(var articolo in articoli)
        
            int id_articolo = articolo.Key;
            foreach (DataRow ra in articolo)
                           
                List<Ordine.Varianti> list_varianti = new List<Ordine.Varianti>();
                var varianti = articolo.Where(r => r.Field<int?>("ID_ART_VAR") == id_articolo);
                foreach (DataRow rv in varianti)
                
                    list_varianti.Add(new Ordine.Varianti(rv.Field<string>("COD_VAR"), id_articolo));
                
                list_articoli.Add(new Ordine.Articoli(id_articolo, ra.Field<string>("TIPO_ART"), ra.Field<string>("COD_ART"), ra.Field<float>("QTA_ART"), ra.Field<int>("ID_OR_ART"), list_varianti));
            
        
        list_ordini.Add(new Ordine(id_ordine, ro.Field<string>("TIPO_OR"), ro.Field<DateTime>("ORA_OR"), Convert.ToBoolean(ro.Field<ulong>("SENT_OR")), ro.Field<int>("ID_OR_CFG"), list_articoli));
    

并且json中该值的返回值如下：

虽然它只需要创建一个数组项，其中所有项都在其中...

所以问题是如何正确地按数据表分组？

我正在尝试按以下数据表进行分组：+ ------- + --------- + ------------------ --- + --------- + ----------- + -------- + ---------- + ---- ---------- + --------- + ----------- + --------- + ------- ----- + | ID_OR ...