Azure 函数的 Cosmos DB 输入绑定无法将 System.String 转换为 System.Guid

Question

I have the following Azure Function

[FunctionName("AllProducts")]
    public static async Task<IActionResult> Run(
        [HttpTrigger(AuthorizationLevel.Anonymous, "get", Route = null)] HttpRequest req,
        [CosmosDB(
            databaseName: "marketplace",
            collectionName: "products",
            SqlQuery = "SELECT * FROM product",
            ConnectionStringSetting = "CosmosDbConnectionString")] IEnumerable<Product> products,
        ILogger log)
    {
        ...some magic here
    }

It is running on .NET Core 3.1 with Azure Functions runtime 3.x. The Product.ID property is Guid . When I send a request to the function I get 500 and in the log stream I see the following message:

Executed 'AllProducts' (Failed, Id=147b3de4-c6f1-445c-80ba-28e75a25ed31, Duration=48ms)Could not cast or convert from System.String to System.Guid.

Is there a way to convert from string to guid without chaning my models?

The model class is as follows:

public class Product
{
    public Guid Id { get; set; }
    [Required]
    public string Name { get; set; }
    [Required]
    public string Description { get; set; }
    public bool IsAvailable { get; set; }
    [ForeignKey("User")]
    public string OwnerName { get; set; }
    public User Owner { get; set; }
}

Answer 1

Please make sure your Id property is not conflicting with the auto generated id property of the document. You can change the property to PropertyID in the document and serialize it accordingly

public class Product
{
    [JsonProperty("PropertyID")]
    public Guid Id { get; set; }
}

Answer 2

CosmosDB has auto generated ID for each document. In my case the auto generated id looks like <Discriminator>|<Auto-generated guid> . This made it unable for the binding to parse the ID it received as a guid. I changed the Product.ID property to Product.ProductID and after that it started working.