LINQ 分组查询

Question

我最初问了一个问题，因为我遇到了一个类似的查询错误，我找到了解决这个问题的帮助，我现在有一个问题/需要一点帮助来了解如何制定正确的退货组，这将用于 WEB API 并且需要以某种方式分组的输出，我无法到达那里。

类-

public class GoodInWarehouseBM
{
    /// <summary>
    /// Pallet Number
    /// </summary>
    public string pallet_identifier { get; set; }

    public List<ShipmentItems> shipment_items { get; set; }

    public class ShipmentItems
    {
        /// <summary>
        /// SKU Code
        /// </summary>
        public string sku { get; set; }

        /// <summary>
        /// Products on Pallet
        /// </summary>
        public decimal stock_qty { get; set; }
        /// <summary>
        /// Description of Item
        /// </summary>
        public string description { get; set; }

    }
}

方法-

public IQueryable<IGrouping<string, GoodInWarehouseBM>> GetWarehouseToStoreList(string storeId)
{
    var entity = (from consighdrs in mi9TestEntities.consighdrs
                  join consigdests in mi9TestEntities.consigdests on consighdrs.consignment equals consigdests.consignment
                  join consigliness in mi9TestEntities.consiglines on consigdests.condestint equals consigliness
                      .condestint
                  join productcodess in mi9TestEntities.productcodes on consigliness.varint equals productcodess.varint
                  join products in mi9TestEntities.products on productcodess.prodint equals products.prodint
                  where consigdests.destination == storeId && consighdrs.status == "T"
                  select new GoodInWarehouseBM()
                  {
                      pallet_identifier = consigdests.consignment,
                      shipment_items = new List<GoodInWarehouseBM.ShipmentItems>
                    {new GoodInWarehouseBM.ShipmentItems
                    {
                        sku = productcodess.variantcode,
                        stock_qty = consigliness.issueqty,
                        description = products.proddesc
                    }}

                  }).GroupBy(x => x.pallet_identifier);

    return entity;
}

输出 -

[
    [
        {
            "pallet_identifier": "FS300057058",
            "shipment_items": [
                {
                    "sku": "051657",
                    "stock_qty": 1,
                    "description": "BELT 1.25\" 5028"
                }
            ]
        },
        {
            "pallet_identifier": "FS300057058",
            "shipment_items": [
                {
                    "sku": "10121781",
                    "stock_qty": 1,
                    "description": "SLAZ CREW SWEAT"
                }
            ]
        },

想要的输出 -

[
  {
    "pallet_identifier": "FS300057058",
    "shipment_items": [
            {
              "sku": "051657",
              "stock_qty": 1,
              "description": "BELT 1.25\" 5028"
            },
            {
              "sku": "10121781",
              "stock_qty": 1,
              "description": "SLAZ CREW SWEAT"
            }
        ]
    }
]

我似乎在这里总结了如何真正得到这个结果，任何帮助和指点都将不胜感激。

Answer 1

重新排序，以便您 GroupBy 然后将每个组选择到您想要的对象中：

...
.GroupBy(x => x.consigdests.consignment)
.Select(x => new GoodInWarehouseBM
{
    pallet_identifier = x.Key,
    shipment_items = x.Select(i => new GoodInWarehouseBM.ShipmentItems
    {
        sku = x.productcodess.variantcode,
        stock_qty = x.consigliness.issueqty,
        description = x.products.proddesc
    }
});

由于我不习惯类似 SQL 的 LINQ 语法，因此您可能不得不稍微调整一下语法。我建议尽可能学习使用基于 lambda 的语法。

Answer 2

您需要在应用分组后选择您的分组结果

...
}).GroupBy(x => x.pallet_identifier)
  .Select(x => new GoodInWarehouseBM { pallet_identifier = x.Key, shipment_items = x.ToList() });

并将您的方法返回类型更改为List<GoodInWarehouseBM> 而不是IQueryable<IGrouping<string, GoodInWarehouseBM>>

或者你可以使用传统的 linq 查询，

var entity = (from consighdrs in mi9TestEntities.consighdrs
...
...
...
where consigdests.destination == storeId && consighdrs.status == "T"
group new { consigdests, productcodess, consigliness, products } by consigdests.consignment into grp
select new GoodInWarehouseBM
{
    pallet_identifier = grp.Key,
    shipment_items = grp.Select(a => new ShipmentItems
    {
        sku  = a.productcodess.variantcode,
        stock_qty = a.consigliness.issueqty,
        description = a.products.proddesc
    })  
}).ToList();