finished the project

HabitTracker.sln

@@ -0,0 +1,25 @@
+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio Version 17
+VisualStudioVersion = 17.11.35327.3
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "HabitTracker", "HabitTracker\HabitTracker.csproj", "{92CE25FA-B589-48E7-B35A-A426F7E1CFDF}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Any CPU = Debug|Any CPU
+		Release|Any CPU = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{92CE25FA-B589-48E7-B35A-A426F7E1CFDF}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{92CE25FA-B589-48E7-B35A-A426F7E1CFDF}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{92CE25FA-B589-48E7-B35A-A426F7E1CFDF}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{92CE25FA-B589-48E7-B35A-A426F7E1CFDF}.Release|Any CPU.Build.0 = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+	GlobalSection(ExtensibilityGlobals) = postSolution
+		SolutionGuid = {875D0802-5575-4A76-8935-8CFBF1874BF4}
+	EndGlobalSection
+EndGlobal

HabitTracker/Credits.cs

@@ -0,0 +1,14 @@
+namespace HabitTracker
+{
+    internal class Credits
+    {
+        static public void GetCredits()
+        {
+            var credits = new List<string>();
+            credits.Add("Created by Nikita Kostin.\n");
+            credits.ForEach(i => Console.Write(i));
+            Console.Write("Press any key to go back to the main menu...");
+            Console.ReadKey();
+        }
+    }
+}

HabitTracker/Data/DbConnection.cs

@@ -0,0 +1,172 @@
+using Microsoft.Data.Sqlite;
+
+namespace HabitTracker.Data
+{
+    public class DbConnection
+    {
+        private static SqliteConnection _connection;
+
+        private DbConnection() { }
+        enum Frequency
+        {
+            Daily,
+            Weekly,
+            Monthly
+        }
+
+        public static SqliteConnection GetConnection(bool isStart = false)
+        {
+            if (_connection == null)
+            {
+                const string dbPath = "testDb.db";
+                _connection = new SqliteConnection($"Data Source={dbPath}");
+                _connection.Open();
+                Console.WriteLine("The database has been connected.");
+
+                if (isStart)
+                {
+                    DbConnection.CreateTable("Habits");
+                    DbConnection.CreateTable("Records");
+                    DbConnection.SeedData();
+                }
+
+
+                _connection.Close();
+            }
+            return _connection;
+        }
+
+        public static void CloseConnection()
+        {
+            if (_connection != null)
+            {
+                _connection.Close();
+                _connection.Dispose();
+                _connection = null;
+                Console.WriteLine("The database connection has been closed.");
+            }
+        }
+
+        public static void CreateTable(string name)
+        {
+            try
+            {
+                var command = _connection.CreateCommand();
+                if (name == "Habits")
+                {
+                    command.CommandText =
+                    @"
+                        CREATE TABLE IF NOT EXISTS Habits (
+                            Id INTEGER PRIMARY KEY AUTOINCREMENT,
+                            Name TEXT NOT NULL,                    
+                            Frequency TEXT NOT NULL,                    
+                            TimesPerPeriod INTEGER NOT NULL,                    
+                            StartDate TEXT NOT NULL                    
+                        )
+                    ";
+                    command.ExecuteNonQuery();
+                }
+                else
+                {
+                    command.CommandText =
+                    @"
+                        CREATE TABLE IF NOT EXISTS Records (
+                            Id INTEGER PRIMARY KEY AUTOINCREMENT,
+                            Name TEXT NOT NULL,                    
+                            HabitDate TEXT NOT NULL,
+                            HabitId INTEGER,
+                            FOREIGN KEY (HabitId) REFERENCES Habits(Id) ON DELETE CASCADE
+                        )
+                    ";
+                    command.ExecuteNonQuery();
+                }
+
+            }
+            catch (Exception ex)
+            {
+                Console.WriteLine("Error creating table: " + ex.Message);
+            }
+
+        }
+
+
+        public static void SeedData()
+        {
+            bool create = false;
+            using (var command = _connection.CreateCommand())
+            {
+                command.CommandText = "SELECT COUNT(*) FROM Habits";
+                long habitCount = (long)command.ExecuteScalar();
+
+                if (habitCount == 0)
+                {
+                    create = true;
+                    Console.WriteLine("Seeding data into the Habits table.");
+                    var random = new Random();
+
+                    for (int i = 0; i < 100; i++)
+                    {
+                        string habitName = $"Habit {i + 1}";
+                        Frequency frequency = (Frequency)random.Next(0, 3); 
+                        string frequencyString = frequency.ToString(); 
+                        int timesPerPeriod = random.Next(1, 5);
+                        string startDate = DateTime.Now.AddDays(-random.Next(0, 100)).ToString("yyyy-MM-dd");
+
+                        command.CommandText =
+                        @"
+                    INSERT INTO Habits (Name, Frequency, TimesPerPeriod, StartDate)
+                    VALUES (@habitName, @frequency, @timesPerPeriod, @startDate)
+                ";
+
+                        command.Parameters.Clear();
+                        command.Parameters.AddWithValue("@habitName", habitName);
+                        command.Parameters.AddWithValue("@frequency", frequencyString);
+                        command.Parameters.AddWithValue("@timesPerPeriod", timesPerPeriod);
+                        command.Parameters.AddWithValue("@startDate", startDate);
+
+                        command.ExecuteNonQuery();
+                    }
+                }
+            }
+
+            if (create)
+            {
+                using (var command = _connection.CreateCommand())
+                {
+                    command.CommandText = "SELECT Id, Name FROM Habits";
+                    using (var reader = command.ExecuteReader())
+                    {
+                        while (reader.Read())
+                        {
+                            int habitId = reader.GetInt32(0);
+                            string habitName = reader.GetString(1);
+
+                            using (var insertCommand = _connection.CreateCommand())
+                            {
+                                for (int j = 0; j < 10; j++)
+                                {
+                                    string habitDate = DateTime.Now.AddDays(-new Random().Next(0, 30)).ToString("yyyy-MM-dd");
+
+                                    insertCommand.CommandText =
+                                    @"
+                                INSERT INTO Records (Name, HabitDate, HabitId)
+                                VALUES (@habitName, @habitDate, @habitId)
+                            ";
+
+                                    insertCommand.Parameters.Clear();
+                                    insertCommand.Parameters.AddWithValue("@habitName", habitName);
+                                    insertCommand.Parameters.AddWithValue("@habitDate", habitDate);
+                                    insertCommand.Parameters.AddWithValue("@habitId", habitId);
+
+                                    insertCommand.ExecuteNonQuery();
+                                }
+                            }
+                        }
+                    }
+                }
+            }
+        }
+
+
+    }
+}