Duplicate id generate

Question

I am creating a project using asp.net core web api and cosmos db. I generate the id as guid value, I auto generate the id.But it create duplicate value.

work.cs file:

 public class work
    {
        [JsonProperty("id")]
        public Guid Id { get; set; }

        [JsonProperty("name")]
        public string name { get; set; }

        public List<Industy> Industy { get; set; }
        public work()
        {
            if (Id == null)
            {
                Id = Guid.NewGuid();
            }
            else
            {
                Id = Id;
            }

        }
    }

Industry.cs file:

    {

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

        [JsonProperty("IdustryId")]
        public int IdustryId { get; set; }

        [JsonProperty("IdustryName")]
        public string IdustryName { get; set; }


        public Industy()
        {
            if (Id == null)
            {
                Id = Guid.NewGuid();
            }
            else
            {
                Id = Id;
            }
        }

    }

output:

  {
    "id": "00000000-0000-0000-0000-000000000000",
    "Name": "string",
    "industy": {
      "id": "00000000-0000-0000-0000-000000000000",
      "IdustryId": 0,
    }
  }

If i enter more than one value without id it show me the error ,id is already exist. please help me to fix it.

Answer 1

Mark public Guid Id { get; set; } as nullable in both models:

public Guid? Id { get; set; }

Guid is a struct and value type. This means you have to compare with its default value instead of null or mark it as nullable.