HW.cs

public class Coffee
{
    public int Id { get; set; }
    public string Name { get; set; }
    public string Description { get; set; }
    public decimal Cost { get; set; }
    public int Grams { get; set; }
    public string Country { get; set; }
}

public class DataAccess
{
    private string connectionString;

    public DataAccess(string connectionString)
    {
        this.connectionString = connectionString;
    }

    public void AddCoffee(Coffee coffee)
    {
        using (var connection = new SqlConnection(connectionString))
        {
            var cmd = new SqlCommand("INSERT INTO Coffees (Name, Description, Cost, Grams, Country) VALUES (@name, @description, @cost, @grams, @country)", connection);
            cmd.Parameters.AddWithValue("@name", coffee.Name);
            cmd.Parameters.AddWithValue("@description", coffee.Description);
            cmd.Parameters.AddWithValue("@cost", coffee.Cost);
            cmd.Parameters.AddWithValue("@grams", coffee.Grams);
            cmd.Parameters.AddWithValue("@country", coffee.Country);
            cmd.ExecuteNonQuery();
        }
    }

    public void UpdateCoffee(Coffee coffee)
    {
        using (var connection = new SqlConnection(connectionString))
        {
            var cmd = new SqlCommand("UPDATE Coffees SET Name = @name, Description = @description, Cost = @cost, Grams = @grams, Country = @country WHERE Id = @id", connection);
            cmd.Parameters.AddWithValue("@id", coffee.Id);
            cmd.Parameters.AddWithValue("@name", coffee.Name);
            cmd.Parameters.AddWithValue("@description", coffee.Description);
            cmd.Parameters.AddWithValue("@cost", coffee.Cost);
            cmd.Parameters.AddWithValue("@grams", coffee.Grams);
            cmd.Parameters.AddWithValue("@country", coffee.Country);
            cmd.ExecuteNonQuery();
        }
    }

    public void DeleteCoffee(int id)
    {
        using (var connection = new SqlConnection(connectionString))
        {
            var cmd = new SqlCommand("DELETE FROM Coffees WHERE Id = @id", connection);
            cmd.Parameters.AddWithValue("@id", id);
            cmd.ExecuteNonQuery();
        }
    }

    public List<Coffee> FindCoffeeByCherryDescription()
    {
        using (var connection = new SqlConnection(connectionString))
        {
            var cmd = new SqlCommand("SELECT * FROM Coffees WHERE Description LIKE '%вишня%'", connection);
            var reader = cmd.ExecuteReader();
            var coffees = new List<Coffee>();
            while (reader.Read())
            {
                coffees.Add(new Coffee
                {
                    Id = (int)reader["Id"],
                    Name = (string)reader["Name"],
                    Description = (string)reader["Description"],
                    Cost = (decimal)reader["Cost"],
                    Grams = (int)reader["Grams"],
                    Country = (string)reader["Country"],
                });
            }
            return coffees;
        }
    }

    public List<Coffee> FindCoffeeByCostRange(decimal minCost, decimal maxCost)
    {
        using (var connection = new SqlConnection(connectionString))
        {
            var cmd = new SqlCommand("SELECT * FROM Coffees WHERE Cost BETWEEN @minCost AND @maxCost", connection);
            cmd.Parameters.AddWithValue("@minCost", minCost);
            cmd.Parameters.AddWithValue("@maxCost", maxCost);
            var reader = cmd.ExecuteReader();
            var coffees = new List<Coffee>();
            while (reader.Read())
            {
                coffees.Add(new Coffee
                {
                    Id = (int)reader["Id"],
                    Name = (string)reader["Name"],
                    Description = (string)reader["Description"],
                    Cost = (decimal)reader["Cost"],
                    Grams = (int)reader["Grams"],
                    Country = (string)reader["Country"],
                });
            }
            return coffees;
        }
    }

    public List<Coffee> FindCoffeeByGramsRange(int minGrams, int maxGrams)
    {
        using (var connection = new SqlConnection(connectionString))
        {
            var cmd = new SqlCommand("SELECT * FROM Coffees WHERE Grams BETWEEN @minGrams AND @maxGrams", connection);
            cmd.Parameters.AddWithValue("@minGrams", minGrams);
        }
    }
}