作为查询不支持cosmos db

Question

我正在尝试下面的代码来获取详细信息，但它没有返回我想要的。

我的查询：

   var query = $"SELECT catalog.id as vendorguid,catalog.VendorName,industry.Id as industryguid,industry.IdustryId,industry.IdustryName,category.id as categoryguid,category.Name as categoryname,category.Description as categorydescription,Subcategory.Id as subcategoryguid,Subcategory.Name as subcategoryname,Subcategory.Description as subcategorydescription,product.Id as productguid,product.Name as productname,product.CurrentQuantity as productCurrentQuantity,product.Tag as productTag,product.ImageUrl as productImageUrl,product.Unit as productUnit,product.Price as productPrice,product.hasMethodOfPreparation as producthasMethodOfPreparation,product.MethodOfPreparation as productMethodOfPreparation,product.Addons as productAddons FROM catalogjoin industry in catalog.Industy join category in industry.Category join Subcategory in category.Subcategoryjoin product in Subcategory.Product where product.Id = '"+productId+"'";

我的服务类别：

输出：

{
      "id": "d91af3e6-6aae-4d10-9ba6-6b97ca4cd881",
      "vendorName": "string",
      "industy": []
    }

预期输出：

{
        "vendorguid": "97392a23-c8c4-4a7f-bffb-7c3807cc40de",
        "VendorName": "string",
        "industryguid": "f8265ee6-a351-4036-a0ee-10ec4f51ecf4",
        "IdustryId": 0,
        "IdustryName": "string",
        "categoryguid": "ce7edfdf-1608-4a8c-ae38-7ca60c43bc30",
        "categoryname": "string",
        "categorydescription": "string",
        "subcategoryguid": "709f4e6f-1bba-421f-8dc0-7cf067cbc032",
        "subcategoryname": "string",
        "subcategorydescription": "string",
        "productguid": "d24dd340-d7a2-42e5-b84a-1ee72d9840c6",
        "productname": "string",
        "productCurrentQuantity": 0,
        "productTag": "string",
        "productImageUrl": [
            "string"
        ],
        "productUnit": 0,
        "productPrice": 0,
        "producthasMethodOfPreparation": true,
        "productMethodOfPreparation": [               
        ],
        "productAddons": [              
        ]
    }

我怎么能得到任何人帮助我？

Answer 1

我认为问题出在您的联接中（类别，子类别）。您确定它总是找到匹配的吗？如果没有找不到匹配项或没有该属性，则CosmosDb将不将其包括在结果集中。

这不像MSSQL的左联接中包含空值。 CosmosDb更像是完全外部联接（交叉联接）。