Eetk6zMQ

1public class DataBase
2    {
3        public static DataBase DB = new DataBase();
4        private NpgsqlConnection conn;
5        NpgsqlCommand cmd = new NpgsqlCommand();
6
7        private const string connectionStr = "Host=localhost;Username=postgres;Password=12345678;Database=postgres";
8
9        public void Connect(string connStr = connectionStr)
10        {
11            conn = new NpgsqlConnection(connStr);
12            conn.Open();
13            cmd.Connection = conn;
14        }
15        // language=postgres
16
17        public void InitDB()
18        {
19            cmd.CommandText = "CREATE TABLE IF NOT EXISTS restaurants(id SERIAL PRIMARY KEY ,name VARCHAR(40))";
20            cmd.ExecuteNonQuery();
21            cmd.CommandText =
22                "CREATE TABLE IF NOT EXISTS workers(id SERIAL PRIMARY KEY,first_name VARCHAR(40),last_name VARCHAR(40),coock_type VARCHAR(30))";
23            cmd.ExecuteNonQuery();
24            cmd.CommandText =
25                "CREATE TABLE IF NOT EXISTS timetable(id SERIAL PRIMARY KEY,restaurant VARCHAR(40),data JSON)";
26            cmd.ExecuteNonQuery();
27
28            cmd.CommandText =
29                "CREATE TABLE IF NOT EXISTS rus(id SERIAL PRIMARY KEY,restaurant VARCHAR(40),date_week DATE,workers VARCHAR(40)[])";
30            cmd.ExecuteNonQuery();
31
32            cmd.CommandText =
33                "CREATE TABLE IF NOT EXISTS italy(id SERIAL PRIMARY KEY,restaurant VARCHAR(40),date_week DATE,workers VARCHAR(40)[])";
34            cmd.ExecuteNonQuery();
35
36            cmd.CommandText =
37                "CREATE TABLE IF NOT EXISTS french(id SERIAL PRIMARY KEY,restaurant VARCHAR(40),date_week DATE,workers VARCHAR(40)[])";
38            cmd.ExecuteNonQuery();
39
40            
41        }
42
43        public string[] GetAllRestaurants()
44        {
45            cmd.Cancel();
46            cmd = new NpgsqlCommand("SELECT name FROM restaurants",conn);
47            var reader = cmd.ExecuteReader();
48            var restaurants = new List<string>();
49            while (reader.Read())
50            {
51                restaurants.Add(reader.GetString(0));
52            }
53
54            return restaurants.ToArray();
55        }
56
57    }