How to update entities from JSON in EF Core

Question

I'm serializing data from EF core to JSON file. My model and configuration:

public class Customer
{
    [Key]
    public Guid Id { get; set; }
    public string Name { get; set; }
    public virtual ICollection<Order> Orders { get; set; }
}

public class Order
{
    [Key]
    public Guid Id { get; set; }
    public Guid CustomerGuid { get; set; }

    [JsonIgnore]
    public virtual Customer Customer { get; set; }

    public string OrderType { get; set; }
}

    public class CustomerConfiguration : IEntityTypeConfiguration<Customer>
    {
        public void Configure(EntityTypeBuilder<Customer> builder)
        {
            builder.HasMany(p => p.Orders).WithOne(d => d.Customer).HasForeignKey(d => d.CustomerGuid);
        }
    }
    public class OrderConfiguration : IEntityTypeConfiguration<Order>
    {
        public virtual void Configure(EntityTypeBuilder<Order> builder)
        {
            builder.HasOne(p => p.Customer).WithMany(p => p.Orders).HasForeignKey(d => d.CustomerGuid);
        }
    }

I serialized one customer to JSON file:

  {
  "Id": "18a55fea-89cd-438a-bae0-4954193807bf",
  "Name": "Customer1",
  "Orders": [
    {
      "Id": "f253837f-5428-405a-880e-2af2b597094c",
      "CustomerGuid": "18a55fea-89cd-438a-bae0-4954193807bf",
      "OrderType": "OrderType1"
    },
    {
      "Id": "0a288fe3-0a00-4372-810f-3d682f82f1dc",
      "CustomerGuid": "18a55fea-89cd-438a-bae0-4954193807bf",
      "OrderType": "OrderType2"
    },
    {
      "Id": "0df4a724-598c-44d7-a6eb-4d597501520f",
      "CustomerGuid": "18a55fea-89cd-438a-bae0-4954193807bf",
      "OrderType": "OrderType0"
    }
  ]
}

Now, I changed "Name": "Customer1" to "Name": "Customer2" from JSON file and I want to update DB also from EF core. I wish in DB customer with "Id": "18a55fea-89cd-438a-bae0-4954193807bf"'s Name would be Customer2. I can delete customer with this Id and create new customer, but I want to update it. In this case, I can do:

 var customerFromJson = JsonConvert.DeserializeObject<Customer>(json);
 var customerFromDB = context.GetEntities<Customer>().Single(c => c.Id == customerFromJson.Id);
 customerFromDB.Name = customerFromJson.Name;
 context.SaveChanges();

But there can be other properties except the Name property and I don't want to do this manually. Is there any good solution, hard codes or other ways to solve this problem?

@Saif, In this case, yes, because I changed only Name from JSON file (From Customer1 to Customer2). — Dilshod K, Dec 04 '19 at 05:59

score 4 · Accepted Answer · answered Dec 04 '19 at 05:31

4

I would suggest to use AutoMapper for this. So you get the entity and map all the fields from your json object into it as:

mapper.Map(customerFromJson, customerFromDB);
context.SaveChanges();

answered Dec 04 '19 at 05:31

Gleb

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score 0 · Answer 2 · answered Dec 04 '19 at 06:43

There is not a trivial way to do this. As was mentioned by Gleb, you could use automapper (got my upvote) but be careful.

The non existing values from your json will become null and the null values will be copied over to the database. So don't forget to add a condition. How to ignore null values for all source members during mapping in Automapper 6?

Another way would be to use reflection and check which properties exist in the destination, based on your json. That's pretty much what automapper does.

Even so, both solutions use reflection which is performance heavy. Your solution for few columns makes the most sense.

AM uses compiled expressions for a long time now. – Lucian Bargaoanu Dec 04 '19 at 07:45 — Lucian Bargaoanu, Dec 04 '19 at 07:45

How to update entities from JSON in EF Core

2 Answers2