App.config

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
    <startup> 
        <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.8" />
    </startup>
	
	<connectionStrings>
		<add name="conn"
		 providerName="System.Data.SqlClient"
		 connectionString="Data Source=localhost;Initial Catalog=Teas;Integrated Security=True;" />
	</connectionStrings>
	
</configuration>

DBController.cs

using System;
using System.Collections.Generic;
using System.Data.SqlClient;
using System.Data;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace DataAdapter
{
    public class DbController
    {
        public void AddTea(string connectionString, string name, string type, float weight, float price, int country_id, string description)
        {
            SqlDataAdapter teaDataAdapter = new SqlDataAdapter("SELECT * FROM Teas", connectionString);

            SqlCommand insertTea = new SqlCommand("INSERT INTO Teas (name, type, weight, price, country_id, description) VALUES (@name, @type, @weight, @price, @country_id, @description); SELECT SCOPE_IDENTITY();", new SqlConnection(connectionString));
            insertTea.Parameters.Add("@name", SqlDbType.NVarChar, 50, "name");
            insertTea.Parameters.Add("@type", SqlDbType.NVarChar, 50, "type");
            insertTea.Parameters.Add("@weight", SqlDbType.Float, 50, "weight");
            insertTea.Parameters.Add("@price", SqlDbType.Float, 50, "price");
            insertTea.Parameters.Add("@country_id", SqlDbType.Int, 50, "country_id");
            insertTea.Parameters.Add("@description", SqlDbType.NVarChar, 50, "description");
            
            teaDataAdapter.InsertCommand = insertTea;

            DataSet dataSet = new DataSet();

            teaDataAdapter.Fill(dataSet, "Teas");

            DataRow newTea = dataSet.Tables["Teas"].NewRow();
            newTea["name"] = name;
            newTea["type"] = type;
            newTea["weight"] = weight;
            newTea["price"] = price;
            newTea["country_id"] = country_id;
            newTea["description"] = description;

            dataSet.Tables["Teas"].Rows.Add(newTea);

            teaDataAdapter.Update(dataSet, "Teas");

            teaDataAdapter.Dispose();
            insertTea.Connection.Dispose();

            Console.WriteLine("Db updated");
        }

        public void AddCountry(string connectionString, string name, float teaAmount)
        {
            SqlDataAdapter countryDataAdapter = new SqlDataAdapter("SELECT * FROM Countries", connectionString);

            SqlCommand insertCountry = new SqlCommand("INSERT INTO Countries (name, tea_amount) VALUES (@name, @tea_amount); SELECT SCOPE_IDENTITY();", new SqlConnection(connectionString));
            insertCountry.Parameters.Add("@name", SqlDbType.NVarChar, 50, "name");
            insertCountry.Parameters.Add("@tea_amount", SqlDbType.Float, 50, "tea_amount");
            
            countryDataAdapter.InsertCommand = insertCountry;

            DataSet dataSet = new DataSet();

            countryDataAdapter.Fill(dataSet, "Countries");

            DataRow newCountry = dataSet.Tables["Countries"].NewRow();
            newCountry["name"] = name;
            newCountry["tea_amount"] = teaAmount;

            dataSet.Tables["Countries"].Rows.Add(newCountry);

            countryDataAdapter.Update(dataSet, "Countries");

            countryDataAdapter.Dispose();
            insertCountry.Connection.Dispose();

            Console.WriteLine("Db updated");
        }

        public void UpdateCountry(string connectionString, int countryId, string name, float teaAmount)
        {
            SqlDataAdapter countryDataAdapter = new SqlDataAdapter("SELECT * FROM Countries WHERE id = @countryId", connectionString);
            countryDataAdapter.SelectCommand.Parameters.AddWithValue("@countryId", countryId);

            SqlCommand updateCountry = new SqlCommand("UPDATE Countries SET name = @name, tea_amount = @tea_amount WHERE id = @countryId", new SqlConnection(connectionString));
            updateCountry.Parameters.AddWithValue("@name", name);
            updateCountry.Parameters.AddWithValue("@tea_amount", teaAmount);
            updateCountry.Parameters.AddWithValue("@countryId", countryId);

            countryDataAdapter.UpdateCommand = updateCountry;

            DataSet dataSet = new DataSet();

            countryDataAdapter.Fill(dataSet, "Countries");

            if (dataSet.Tables["Countries"].Rows.Count > 0)
            {
                dataSet.Tables["Countries"].Rows[0]["name"] = name;
                dataSet.Tables["Countries"].Rows[0]["tea_Amount"] = teaAmount;

                countryDataAdapter.Update(dataSet, "Countries");
                Console.WriteLine("Country updated");
            }
            else
            {
                Console.WriteLine("Id not found");
            }

            countryDataAdapter.Dispose();
            updateCountry.Connection.Dispose();
        }

        public void UpdateTea(string connectionString, int teaId, string name, string type, float weight, float price, int country_id, string description)
        {
            SqlDataAdapter teaDataAdapter = new SqlDataAdapter("SELECT * FROM Teas WHERE id = @teaId", connectionString);
            teaDataAdapter.SelectCommand.Parameters.AddWithValue("@teaId", teaId);

            SqlCommand updateTea = new SqlCommand("UPDATE Teas SET name = @name, type = @type, weight = @weight, price = @price, country_id = @country_id, description = @description WHERE id = @teaId", new SqlConnection(connectionString));

            updateTea.Parameters.AddWithValue("@name", name);
            updateTea.Parameters.AddWithValue("@type", type);
            updateTea.Parameters.AddWithValue("@weight", weight);
            updateTea.Parameters.AddWithValue("@price", price);
            updateTea.Parameters.AddWithValue("@country_id", country_id);
            updateTea.Parameters.AddWithValue("@description", description);
            updateTea.Parameters.AddWithValue("@teaId", teaId);

            teaDataAdapter.UpdateCommand = updateTea;

            DataSet dataSet = new DataSet();

            teaDataAdapter.Fill(dataSet, "Teas");

            if (dataSet.Tables["Teas"].Rows.Count > 0)
            {
                dataSet.Tables["Teas"].Rows[0]["name"] = name;
                dataSet.Tables["Teas"].Rows[0]["type"] = type;
                dataSet.Tables["Teas"].Rows[0]["weight"] = weight;
                dataSet.Tables["Teas"].Rows[0]["price"] = price;
                dataSet.Tables["Teas"].Rows[0]["country_id"] = country_id;
                dataSet.Tables["Teas"].Rows[0]["description"] = description;

                teaDataAdapter.Update(dataSet, "Teas");
                Console.WriteLine("Tea updated");
            }
            else
            {
                Console.WriteLine("Id not found");
            }

            teaDataAdapter.Dispose();
            updateTea.Connection.Dispose();
        }

        public void DeleteTea(string connectionString, int teaId)
        {
            SqlDataAdapter teaDataAdapter = new SqlDataAdapter("SELECT * FROM Teas WHERE id = @teaId", connectionString);
            teaDataAdapter.SelectCommand.Parameters.AddWithValue("@teaId", teaId);

            SqlCommand deleteTea = new SqlCommand("DELETE FROM Teas WHERE id = @teaId", new SqlConnection(connectionString));
            deleteTea.Parameters.AddWithValue("@teaId", teaId);

            teaDataAdapter.DeleteCommand = deleteTea;

            DataSet dataSet = new DataSet();

            teaDataAdapter.Fill(dataSet, "Teas");

            if (dataSet.Tables["Teas"].Rows.Count > 0)
            {
                dataSet.Tables["Teas"].Rows[0].Delete();
                teaDataAdapter.Update(dataSet, "Teas");
                Console.WriteLine("Tea deleted");
            }
            else
            {
                Console.WriteLine("Id not found");
            }

            teaDataAdapter.Dispose();
            deleteTea.Connection.Dispose();
        }

        public void DeleteCountry(string connectionString, int countryId)
        {
            SqlDataAdapter countryDataAdapter = new SqlDataAdapter("SELECT * FROM Countries WHERE id = @countryId", connectionString);
            countryDataAdapter.SelectCommand.Parameters.AddWithValue("@countryId", countryId);

            SqlCommand deleteCountry = new SqlCommand("DELETE FROM Countries WHERE id = @countryId", new SqlConnection(connectionString));
            deleteCountry.Parameters.AddWithValue("@countryId", countryId);

            countryDataAdapter.DeleteCommand = deleteCountry;

            DataSet dataSet = new DataSet();

            countryDataAdapter.Fill(dataSet, "Countries");

            if (dataSet.Tables["Countries"].Rows.Count > 0)
            {
                dataSet.Tables["Countries"].Rows[0].Delete();
                countryDataAdapter.Update(dataSet, "Countries");
                Console.WriteLine("Country deleted");
            }
            else
            {
                Console.WriteLine("Id not found");
            }

            countryDataAdapter.Dispose();
            deleteCountry.Connection.Dispose();
        }

        public void DeleteAll(string connectionString)
        {
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                connection.Open();

                using (SqlCommand deleteTeasCommand = new SqlCommand("DELETE FROM Teas", connection))
                {
                    deleteTeasCommand.ExecuteNonQuery();
                }
                using (SqlCommand deleteCountriesCommand = new SqlCommand("DELETE FROM Countries", connection))
                {
                    deleteCountriesCommand.ExecuteNonQuery();
                }
            }
        }
    }
}

main.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Configuration;
using System.Data.SqlClient;
using System.Data;

namespace DataAdapter
{
    internal class Program
    {
        private static DbController dbController = new DbController();
        private static Printer printer = new Printer();
        private static string conn = ConfigurationManager.ConnectionStrings["conn"].ConnectionString;

        static void Main(string[] args)
        {
            dbController.AddTea(conn, "chanchun", "green", 1, 120, 1, "Tea 1");
            dbController.AddTea(conn, "linlin", "black", 22, 200, 1, "Tea 2");
            dbController.AddTea(conn, "saosen", "black", 2, 999, 1, "Tea 3");

            dbController.AddCountry(conn, "America", 200);
            dbController.AddCountry(conn, "Romania", 10);
            dbController.AddCountry(conn, "France", 99);
            dbController.AddCountry(conn, "China", 79);
            dbController.AddCountry(conn, "Japan", 29);

            dbController.UpdateCountry(conn, 1, "Romania", 18000);
            dbController.UpdateTea(conn, 3, "SAUSEP", "yellow", 120, 30, 2, "UPD");

            dbController.DeleteTea(conn, 3);
            dbController.DeleteCountry(conn, 3);

            printer.PrintByType(conn, "green");
            printer.PrintByPrice(conn, 100, 300);
            printer.PrintByWeight(conn, 1, 3);
            printer.PrintByCountry(conn, 1050);
            printer.Top3ByQuantity(conn);
            printer.Top3GreenByWeight(conn);
            printer.Top3BlackByWeight(conn);
            printer.Top3TeasByWeight(conn);

            dbController.DeleteAll(conn);

        }
    }
}

Printer.cs

using System;
using System.Collections.Generic;
using System.Data.SqlClient;
using System.Data;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace DataAdapter
{
    public class Printer
    {
        public void PrintByType(string connectionString, string type)
        {
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                connection.Open();

                SqlDataAdapter adapter = new SqlDataAdapter("SELECT * FROM Teas WHERE type = @type", connection);
                adapter.SelectCommand.Parameters.AddWithValue("@type", type);

                DataSet dataSet = new DataSet();
                adapter.Fill(dataSet);

                if (dataSet.Tables.Count > 0 && dataSet.Tables[0].Rows.Count > 0)
                {
                    Console.WriteLine("Teas with type " + type + ":");

                    foreach (DataRow row in dataSet.Tables[0].Rows)
                    {
                        Console.WriteLine($"ID: {row["id"]}, Name: {row["name"]}, Type: {row["type"]}, Weight: {row["weight"]}, Price: {row["price"]}, Country_ID: {row["country_id"]}, Description: {row["description"]}");
                    }
                }
                else
                {
                    Console.WriteLine("No teas found");
                }
            }

            Console.WriteLine();
        }

        public void PrintByPrice(string connectionString, float minPrice, float maxPrice)
        {
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                connection.Open();

                SqlDataAdapter adapter = new SqlDataAdapter("SELECT * FROM Teas WHERE price >= @minPrice AND price <= @maxPrice", connection);
                adapter.SelectCommand.Parameters.AddWithValue("@minPrice", minPrice);
                adapter.SelectCommand.Parameters.AddWithValue("@maxPrice", maxPrice);

                DataSet dataSet = new DataSet();
                adapter.Fill(dataSet);

                if (dataSet.Tables.Count > 0 && dataSet.Tables[0].Rows.Count > 0)
                {
                    Console.WriteLine($"Teas with price between {minPrice} and {maxPrice}:");

                    foreach (DataRow row in dataSet.Tables[0].Rows)
                    {
                        Console.WriteLine($"ID: {row["id"]}, Name: {row["name"]}, Type: {row["type"]}, Weight: {row["weight"]}, Price: {row["price"]}, Country_ID: {row["country_id"]}, Description: {row["description"]}");
                    }
                }
                else
                {
                    Console.WriteLine($"No teas found");
                }
            }

            Console.WriteLine();
        }

        public void PrintByWeight(string connectionString, float minWeight, float maxWeight)
        {
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                connection.Open();

                SqlDataAdapter adapter = new SqlDataAdapter("SELECT * FROM Teas WHERE weight >= @minWeight AND weight <= @maxWeight", connection);
                adapter.SelectCommand.Parameters.AddWithValue("@minWeight", minWeight);
                adapter.SelectCommand.Parameters.AddWithValue("@maxWeight", maxWeight);

                DataSet dataSet = new DataSet();
                adapter.Fill(dataSet);

                if (dataSet.Tables.Count > 0 && dataSet.Tables[0].Rows.Count > 0)
                {
                    Console.WriteLine($"Teas with weight between {minWeight} and {maxWeight}:");

                    foreach (DataRow row in dataSet.Tables[0].Rows)
                    {
                        Console.WriteLine($"ID: {row["id"]}, Name: {row["name"]}, Type: {row["type"]}, Weight: {row["weight"]}, Price: {row["price"]}, Country_ID: {row["country_id"]}, Description: {row["description"]}");
                    }
                }
                else
                {
                    Console.WriteLine($"No teas found");
                }
            }

            Console.WriteLine();
        }

        public void PrintByCountry(string connectionString, int countryId)
        {
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                connection.Open();

                string query = "SELECT t.*, c.Name AS CountryName FROM Teas t INNER JOIN Countries c ON t.country_id = c.id WHERE c.id = @countryId";
                SqlDataAdapter adapter = new SqlDataAdapter(query, connection);
                adapter.SelectCommand.Parameters.AddWithValue("@countryId", countryId);

                DataSet dataSet = new DataSet();
                adapter.Fill(dataSet);

                if (dataSet.Tables.Count > 0 && dataSet.Tables[0].Rows.Count > 0)
                {
                    Console.WriteLine("Teas in country " + dataSet.Tables[0].Rows[0]["CountryName"] + ":");

                    foreach (DataRow row in dataSet.Tables[0].Rows)
                    {
                        Console.WriteLine($"ID: {row["id"]}, Name: {row["name"]}, Type: {row["type"]}, Weight: {row["weight"]}, Price: {row["price"]}, Country: {row["CountryName"]}, Description: {row["description"]}");
                    }
                }
                else
                {
                    Console.WriteLine("No teas found");
                }
            }

            Console.WriteLine();
        }

        public void Top3ByQuantity(string connectionString)
        {
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                connection.Open();

                SqlDataAdapter adapter = new SqlDataAdapter("SELECT TOP 3 * FROM Countries ORDER BY tea_amount DESC", connection);

                DataSet dataSet = new DataSet();
                adapter.Fill(dataSet);

                if (dataSet.Tables.Count > 0 && dataSet.Tables[0].Rows.Count > 0)
                {
                    Console.WriteLine("Top 3 countries by tea_amount:");

                    foreach (DataRow row in dataSet.Tables[0].Rows)
                    {
                        Console.WriteLine($"ID: {row["id"]}, Name: {row["name"]}, Tea Amount: {row["tea_amount"]}");
                    }
                }
                else
                {
                    Console.WriteLine("No countries found");
                }
            }

            Console.WriteLine();
        }

        public void Top3GreenByWeight(string connectionString)
        {
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                connection.Open();

                SqlDataAdapter adapter = new SqlDataAdapter("SELECT TOP 3 * FROM Teas WHERE type = 'green' ORDER BY weight DESC", connection);

                DataSet dataSet = new DataSet();
                adapter.Fill(dataSet);

                if (dataSet.Tables.Count > 0 && dataSet.Tables[0].Rows.Count > 0)
                {
                    Console.WriteLine("Top 3 green teas by weight:");

                    foreach (DataRow row in dataSet.Tables[0].Rows)
                    {
                        Console.WriteLine($"ID: {row["id"]}, Name: {row["name"]}, Type: {row["type"]}, Weight: {row["weight"]}, Price: {row["price"]}, Country_ID: {row["country_id"]}, Description: {row["description"]}");
                    }
                }
                else
                {
                    Console.WriteLine("No green teas found");
                }
            }

            Console.WriteLine();
        }

        public void Top3BlackByWeight(string connectionString)
        {
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                connection.Open();

                SqlDataAdapter adapter = new SqlDataAdapter("SELECT TOP 3 * FROM Teas WHERE type = 'black' ORDER BY weight DESC", connection);

                DataSet dataSet = new DataSet();
                adapter.Fill(dataSet);

                if (dataSet.Tables.Count > 0 && dataSet.Tables[0].Rows.Count > 0)
                {
                    Console.WriteLine("Top 3 black teas by weight:");

                    foreach (DataRow row in dataSet.Tables[0].Rows)
                    {
                        Console.WriteLine($"ID: {row["id"]}, Name: {row["name"]}, Type: {row["type"]}, Weight: {row["weight"]}, Price: {row["price"]}, Country_ID: {row["country_id"]}, Description: {row["description"]}");
                    }
                }
                else
                {
                    Console.WriteLine("No black teas found");
                }
            }

            Console.WriteLine();
        }

        public void Top3TeasByWeight(string connectionString)
        {
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                connection.Open();

                SqlDataAdapter adapter = new SqlDataAdapter("SELECT TOP 3 * FROM Teas ORDER BY weight DESC", connection);

                DataSet dataSet = new DataSet();
                adapter.Fill(dataSet);

                if (dataSet.Tables.Count > 0 && dataSet.Tables[0].Rows.Count > 0)
                {
                    Console.WriteLine("Top 3 teas by weight:");

                    foreach (DataRow row in dataSet.Tables[0].Rows)
                    {
                        Console.WriteLine($"ID: {row["id"]}, Name: {row["name"]}, Type: {row["type"]}, Weight: {row["weight"]}, Price: {row["price"]}, Country_ID: {row["country_id"]}, Description: {row["description"]}");
                    }
                }
                else
                {
                    Console.WriteLine("No teas found");
                }
            }

            Console.WriteLine();
        }

    }
}