How to store JSON in an entity field with EF Core?

Question

I am creating a reusable library using .NET Core (targeting .NETStandard 1.4) and I am using Entity Framework Core (and new to both). I have an entity class that looks like

Answer 1

The key to making the the Change Tracker function correctly is to implement a ValueComparer as well as a ValueConverter. Below is an extension to implement such:

public static class ValueConversionExtensions
{
    public static PropertyBuilder HasJsonConversion(this PropertyBuilder propertyBuilder) where T : class, new()
    {
        ValueConverter converter = new ValueConverter
        (
            v => JsonConvert.SerializeObject(v),
            v => JsonConvert.DeserializeObject(v) ?? new T()
        );

        ValueComparer comparer = new ValueComparer
        (
            (l, r) => JsonConvert.SerializeObject(l) == JsonConvert.SerializeObject(r),
            v => v == null ? 0 : JsonConvert.SerializeObject(v).GetHashCode(),
            v => JsonConvert.DeserializeObject(JsonConvert.SerializeObject(v))
        );

        propertyBuilder.HasConversion(converter);
        propertyBuilder.Metadata.SetValueConverter(converter);
        propertyBuilder.Metadata.SetValueComparer(comparer);
        propertyBuilder.HasColumnType("jsonb");

        return propertyBuilder;
    }
}

Example of how this works.

public class Person
{
    public int Id { get; set; }

    [Required]
    [MaxLength(50)]
    public string FirstName { get; set; }

    [Required]
    [MaxLength(50)]
    public string LastName { get; set; }

    [Required]
    public DateTime DateOfBirth { get; set; }

    public List
 Addresses { get; set; }      
}

public class Address
{
    public string Type { get; set; }
    public string Company { get; set; }
    public string Number { get; set; }
    public string Street { get; set; }
    public string City { get; set; }
}

public class PersonsConfiguration : IEntityTypeConfiguration
{
    public void Configure(EntityTypeBuilder builder)
    {
        // This Converter will perform the conversion to and from Json to the desired type
        builder.Property(e => e.Addresses).HasJsonConversion>();
    }
}

This will make the ChangeTracker function correctly.