How to project data into a new table?

Question

C++ / C#

There is a first model

public class Case
    {
        public int Id { get; set; }
        public string caseName { get; set; }
        public int caseNumber { get; set; }
        public string caseShortName { get; set; }
        public Price Price { get; set; }
    }

Second model

public class Price
    {
        public int Id { get; set; }
        public double casePrice { get; set; }
        public int CaseId { get; set; }
        public Case Case { get; set; }
    }

and the third model, where the name of the case and its price will be projected

public class PriceName
    {
        public int Id { get; set; }
        public string Name { get; set; }
        public double TotalPrice { get; set; }
    }

Main code

public class ApplicationContext : DbContext
    {
        public DbSet<Case> Cases { get; set; } = null!;
        public DbSet<Price> Prices { get; set; } = null!;
        public DbSet<PriceName> PriceNames { get; set; } = null!;
        public ApplicationContext()
        {
        }

        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
        {
            optionsBuilder.UseNpgsql("Server = localhost; Port = 5433; Database = test; Username = postgres; Password = root");
        }

    }

class Program
    {
        static void Main(string[] args)
        {
            using(ApplicationContext db = new ApplicationContext())
            {
                db.Database.EnsureDeleted();
                db.Database.EnsureCreated();
                Case riptide = new Case { caseName = "Operation Riptide Case",  caseNumber = 176264317, caseShortName = "riptide"};
                Case glove = new Case { caseName = "Gloves Case", caseNumber = 175854202, caseShortName = "gloves" };
                Case spectrum = new Case { caseName = "Spectrum Case", caseNumber = 175880240, caseShortName = "spectrum" };
                Case prisma = new Case { caseName = "Prisma Case", caseNumber = 176042493, caseShortName = "prisma" };
                Case fracture = new Case { caseName = "Fracture Case", caseNumber = 176185874, caseShortName = "fracture" };
                Case gamma = new Case { caseName = "Gamma Case", caseNumber = 156110183, caseShortName = "gamma" };
                Case bloodhound = new Case { caseName = "BloodHound Case", caseNumber = 49359031, caseShortName = "bloodhound" };
                Case revolver = new Case { caseName = "Revolver Case", caseNumber = 84444464, caseShortName = "revolver" };


                db.Cases.AddRange(riptide, glove, spectrum, prisma, fracture, gamma, bloodhound, revolver);
                db.SaveChanges();

                Price riptidePrice = new Price { casePrice = 0.58, Case = riptide };
                Price glovePrice = new Price { casePrice = 1.84, Case = glove };
                Price spectrumPrice = new Price { casePrice = 0.61, Case = spectrum };
                Price prismaPrice = new Price { casePrice = 0.07, Case = prisma };
                Price fracturePrice = new Price { casePrice = 0.07, Case = fracture };
                Price gammaPrice = new Price { casePrice = 0.35, Case = gamma };
                Price bloodhoundPrice = new Price { casePrice = 0.50, Case = bloodhound };
                Price revolverPrice = new Price { casePrice = 0.12, Case = revolver };

                db.Prices.AddRange(riptidePrice, glovePrice, spectrumPrice, prismaPrice, fracturePrice, gammaPrice, bloodhoundPrice, revolverPrice);
                db.SaveChanges();
            }

          
        }
    }

and the second applicationcontext where the data will be projected, here comes a request from a user like give the price of a case called riptide. and this result should appear in the database in a table

using(ApplicationContext db = new ApplicationContext())
            {
                var report = db.Cases.Where(x => x.caseShortName == "riptide").Select(s => new PriceName
                {
                    Name = s.caseName,
                    TotalPrice = s.Price.casePrice
                });
            }

but my data does not appear in the pricename table and the connection is busy error occurs.