Question

我已经为我的EF6数据库模型配置了一个RESTier接口，并定义了一个以国家代码为参数的操作。

此操作返回公司库存中的产品列表（类型为InvMaster的对象），每个InvMaster对象具有来自不同供应商价格表的一个或多个价格。 JSON模型如下所示：

{
     @ odata.context = http: //localhost:60414/restier/$metadata#InvMaster(StockCode,Description,LongDesc,ProductClass,InvMaster_,Gw_ItemPrice,InvMaster_(Brand,Manufacturer),Gw_ItemPrice(ItemPriceID,PriceListed,PriceListID,Gw_PriceList,Gw_PriceList(ApSupplier(Currency,SupplierName))))
        "@odata.count": 104,
    "value":
    [{
            "StockCode": "AVI000001",
            "Description": "Bakers Choice Assorted",
            "LongDesc": "12 x 200 g",
            "ProductClass": "01010SnackSweetBisc",
            "InvMaster_": {
                "Brand": "Bakers",
                "Manufacturer": "National Brands"
            },
            "Gw_ItemPrice":
            [{
                    "PriceListed": 308.6000,
                    "ItemPriceID": 1
                }, {
                    "PriceListed": 239.2200,
                    "ItemPriceID": 2
                }
            ]
        }
    ]
}

在操作中，我使用传入的国家/地区代码，以及一些其他逻辑来确定可用价格的优先顺序，并使用一系列有序价格返回库存物品。但是，我只希望对客户端应用程序上显示的项目执行此排序逻辑（IE：应用$ filter，$ skip和$ top逻辑后）

例如，如果在我的客户端应用程序上，用户每页选择50个项目，那么$ top = 50＆amp; $ skip = ??将通过查询选项以及对我的操作的调用发送。最终，正确的数据被发回，但在我的操作中，我正在遍历库存中的每个项目并对价格进行排序，然后查询选项最终用于仅过滤掉所请求的条目。 我需要在执行计算之前应用查询选项，否则这是一个非常慢的操作，每次请求具有价格的项目时都会执行大量无用的工作。我对如何实现这一点的理解是在操作中使用查询选项...我想这些将是OdataQueryOptions ...但我不知道如何访问它们。请帮忙。

以下是该操作的基本结构：

    [Operation(EntitySet = "InvMaster")]
    [EnableQuery]
    public IQueryable<InvMaster> GetItemsWithPrioritisedPrices(string destination)
    {
        // Get the inventory items which are being requested
        // TODO: How do I use the ODataQueryOptions from the query?!? Worried about performance.
        // Surely I need to apply $top, $skip to the query below?!?!?!?!
        // This operation will be perfectly happy if we only have to deal with 10, 20 or even 50 inventory items at a time.
        // Otherwise we land in the dwang.
        var items = ModelContext.InvMaster
                         .Include(i => i.InvMaster_)
                         .Include(i => i.InvAltSupplier)
                         //.Take(10)
                         .ToList()
                         .AsQueryable();
                         // TODO: Check what is hitting the database from this query.

        var itemsPricesOrdered = new List<InvMaster>();

        foreach (var item in items)
        {
            var pricesOrdered = new List<Gw_ItemPrice>();
            // List to hold all available suppliers for each stock item.
            var validSuppliers = new List<string>();

            // Stock item has Default Supplier and alternate suppliers (InvAltSupplier).
            // First add the alternate Suppliers.
            foreach (var supplier in item.InvAltSupplier)
            {
                validSuppliers.Add(supplier.Supplier);
            }

            // Finally add the default supplier for the item.
            validSuppliers.Add(item.Supplier);

            try
            {
                // Get available price lists for this stock code and supplier
                var prices = ModelContext.Gw_ItemPrice
                            //.Where(e => e.Gw_PriceList.Supplier == supplier)
                            .Where(e => e.StockCode == item.StockCode)
                            .Where(e => e.Gw_PriceList.Gw_PriceStatus.PriceStatusID == 3)
                            .Include(e => e.Gw_PriceList)
                            .Include(e => e.Gw_PriceList.ApSupplier)
                            .ToList();

                foreach (var price in prices)
                {
                    // Initialise warning flags to false.
                    price.MarketRestricted = false;
                    price.DateExpired = false;
                    price.DefaultSupplier = false; //currently not used.

                    // Do the logic to order prices as required.
                    // should only order prices for the entries that need to be returned.
                }

如何访问RESTier Operation

0 个答案: