db_AI-4/csharp/marketconnectionNET2.0/db_AI-4_V3/db_AI-4/DataAccess.cs

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

namespace db_AI_4
{
    public class DataAccess
    {
        public SqlConnection connection { get; private set; }

        //Read locations from the Database function start
        public List<GetLocations> GetLocations(string LocationName)
        {
            using (IDbConnection connection = new System.Data.SqlClient.SqlConnection(Helper.CnnVal("marketdb")))
            {

                var output = connection.Query<GetLocations>($"SELECT * FROM locations WHERE location_name like '%{ LocationName }%'").ToList();
                return output;

            }
        }
        // im moment nicht benötigt (sollte die id des momentanen members herauslesen)
        public List<GetMembers> DisplayUser(string Email_address)
        {
            using (IDbConnection connection = new System.Data.SqlClient.SqlConnection(Helper.CnnVal("marketdb")))
            {
                var outputUser = connection.Query<GetMembers>($"SELECT member_id FROM dbo.members WHERE email_address = '{Email_address}'").ToList();
                return outputUser;
            }
        }
        //Read locations from the Database function end



        // Insert Locations into Database start
        public void InsertLocations(string StreetName, int LocationCapacity, string LocationName)
        {
            using (IDbConnection connection = new System.Data.SqlClient.SqlConnection(Helper.CnnVal("marketdb")))
            {
                List<GetLocations> locations = new List<GetLocations>();

                locations.Add(new GetLocations { streetname = StreetName, location_capacity = LocationCapacity, location_name = LocationName });

                connection.Execute("INSERT INTO dbo.locations (streetname, location_capacity, location_name)" +
                    " VALUES (@streetName, @location_capacity, @location_name)", locations);
            }
        }
        // Insert Locations into Database end



        // Insert Rents into Database start
        public void InsertRent(string RentDate,  int MemberID, int RentPriceID )
        {
            using (IDbConnection connection = new System.Data.SqlClient.SqlConnection(Helper.CnnVal("marketdb")))
            {
                List<GetRents> rents = new List<GetRents>();

                rents.Add(new GetRents { rent_date = RentDate,  member_id = 1, rent_price_id = RentPriceID, location_id = 1});

                connection.Execute("INSERT INTO dbo.rents (rent_date, member_id, rent_price_id, location_id)" +
                    " VALUES (@rent_date, @member_id, @rent_price_id, @location_id )", rents);
            }
        }
        // Insert Rents into Database end



        //Registration function start
        public void InsertMember(string Email_address, string Password)
        {
            using (IDbConnection connection = new System.Data.SqlClient.SqlConnection(Helper.CnnVal("marketdb")))
            {

                List<GetMembers> members = new List<GetMembers>();

                members.Add(new GetMembers { email_address = Email_address, password = Password });

                connection.Execute("INSERT INTO dbo.members ( email_address, password)" +
                    " VALUES (@Email_address, @Password) ", members);

            }
        }
        //Registration function end

        //Read Rented locations start
        internal List<GetRents> GetRentedLocations(string LocationName)
        {
            using (IDbConnection connection = new System.Data.SqlClient.SqlConnection(Helper.CnnVal("marketdb")))
            {

                var rentoutput = connection.Query<GetRents>( $"SELECT * FROM [RentedLocations] WHERE location_name like '%{ LocationName }%' ORDER BY rent_date ASC ").ToList();
                return rentoutput;

            }
        }

        //Read Rented locations end



        //CheckLogin function start
        public void CheckLogin(string Email_address, string Password)
        {
            SqlConnection con = new SqlConnection(Helper.CnnVal("marketdb"));

                con.Open();
                SqlCommand cmd = new SqlCommand($"SELECT * FROM dbo.members WHERE email_address = '{Email_address}' and password = '{Password}'",con);
                SqlDataReader reader;
                reader = cmd.ExecuteReader();

                int count = 0;
                while (reader.Read())
                {
                    count += 1;
                }

                if (count == 1)
                {
                    MessageBox.Show("It Worked");
                    Dashboard dashboard = new Dashboard();
                    dashboard.Show();
                }
                else if (count > 0)
                {
                    MessageBox.Show("Already existing");
                }
                else
                {
                    MessageBox.Show("Username or Password not correct");

                }
            //CheckLogin function end
        }
    }
}