Problem with nested type in jsonb column

After creating Db context like below:

public class MyDbContext<T> : DbContext
        where T : class
    {
        private readonly string connectionString;

        private readonly string table;

        public MyDbContext(string connectionString, string table)
        {
            this.connectionString = connectionString;
            this.table = table;
        }

        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
        {
            optionsBuilder.UseNpgsql(connectionString);
        }

        protected override void OnModelCreating(ModelBuilder modelBuilder)
        {
            var entityTypeBuilder = modelBuilder.Entity<T>();
            entityTypeBuilder.Property("Values").HasColumnType("jsonb");

            entityTypeBuilder.ToTable(table, "public").HasNoKey();
        }
    }

and below row is in database:

-------------------------------------------------------------------------------------------------------------
|           Id                           |                    Values                                        |
-------------------------------------------------------------------------------------------------------------
| f92df955-50fc-4037-bd2f-4df1550a167f   |  {"_Item": {"a": 10}, "b": "bValue", "c": "cValue",  "f": true}  |
-------------------------------------------------------------------------------------------------------------

my classes is like below:

public class DbClass
{
    public Guid Id { get; set; }

    public OuterClass Values { get; set; }
}

public class OuterClass 
{
    public InnerClass _Item { get; set; }

    public string b { get; set; }

    public string c { get; set; }

    public bool f { get; set; }
}

public class InnerClass
{
    public int a { get; set; }
}

querying with dbContext throws below exception:

No coercion operator is defined between types 'System.String' and 'InnerClass'.

Am i doing something wrong?!

[roji]

@RZProf you always have the possibility of getting the entire JSON document out of the database, and then project out your Guid/TimeSpan in .NET (by using AsEnumerable/AsEnumerableAsync before the final projection). This will fetch more data than you actually need, but at the moment I can’t really dive deeper into it… EF Core 7 will probably have a significant focus around JSON, so this issue will probably go away, but most probably not for EF Core 6.

[roji]

Thanks for the extra info. I’ll try to look into this at some point, in order to provide a fix that wouldn’t require the operator.