c# tutorial for beginners - hotel management system project

 using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

using System.Windows.Forms;

using System.Data.SqlClient;

namespace Book__room

{

    public partial class Form3 : Form

    {

        public Form3()

        {

            InitializeComponent();

        }

        SqlConnection conn = new SqlConnection("Data Source=.;Initial catalog=hotel;Integrated Security=true");

        string strsql;

        SqlCommand cmd;

        private void button1_Click(object sender, EventArgs e)

        {

            strsql = "insert into table1(room,startdate,enddate)Values(@room1,@start1,@end1)";

            cmd = new SqlCommand(strsql, conn);

            cmd.Parameters.AddWithValue("room1", comboBox1.Text);

            cmd.Parameters.AddWithValue("start1", dateTimePicker1.Value.ToString());

            cmd.Parameters.AddWithValue("end1", dateTimePicker2.Value.ToString());

            conn.Open();

            cmd.ExecuteNonQuery();

            conn.Close();

            MessageBox.Show("The room reserved successfully");

        }

        private void button2_Click(object sender, EventArgs e)

        {

            conn.Open();

            strsql = "Select * from table1 Where room=@room1 " +

                "And ((@start1 >= startdate And @end1 <= enddate)" +

                "Or (@start1 <= startdate And @end1 >= enddate)" +

                "or (@start1 > startdate And @end1 > enddate And @start1<enddate)" +

                "or (@start1 < startdate And @end1 < enddate And @end1>startdate))";

            cmd = new SqlCommand(strsql, conn);

            cmd.Parameters.AddWithValue("room1", comboBox1.Text);

            cmd.Parameters.AddWithValue("start1", dateTimePicker1.Value.ToString());

            cmd.Parameters.AddWithValue("end1", dateTimePicker2.Value.ToString());

            SqlDataReader myreader = cmd.ExecuteReader();

            if (myreader.Read())

            {

                MessageBox.Show("The room reserved From: " + myreader.GetValue(2).ToString() + " To: " + myreader.GetValue(3).ToString());

            }

            else

            {

                MessageBox.Show("The room not reserved before");

            }

            conn.Close();

        }

    }

}

Visual Basic.net: insert date and check a date between two dates in access database(system book room in a hotel)

 Imports System.Data.OleDb

Public Class Form6

    Dim conn As New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=E:\dd.mdb")

    Private Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click

        Dim strsql1 As String

        strsql1 = "insert into table1(room1,startdate1,enddate1)Values(@room,@start1,@end1)"

        Dim cmd1 As New OleDbCommand(strsql1, conn)

        cmd1.Parameters.AddWithValue("@room", OleDbType.VarChar).Value = ComboBox1.Text

        cmd1.Parameters.AddWithValue("@start1", OleDbType.Date).Value = DateTimePicker1.Value.ToString

        cmd1.Parameters.AddWithValue("@end1", OleDbType.Date).Value = DateTimePicker2.Value.ToString

        conn.Open()

        cmd1.ExecuteNonQuery()

        conn.Close()

        MessageBox.Show("The Room reserved successfully")

    End Sub

  

    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click

        conn.Open()

        Dim strsql2 As String

        strsql2 = " Select * from table1 where room1=@room " & _

            " And ((@start1>=startdate1 and @end1<= enddate1)" & _

            " or (@start1<=startdate1 and @end1>= enddate1)" & _

            " or (@start1>startdate1 and @end1> enddate1 and @start1 <enddate1 )" & _

            " or (@start1<startdate1 and @end1< enddate1 and @end1 >startdate1 ))"

        Dim cmd2 As New OleDbCommand(strsql2, conn)

        cmd2.Parameters.AddWithValue("@room", OleDbType.VarChar).Value = ComboBox1.Text

        cmd2.Parameters.AddWithValue("@start1", OleDbType.Date).Value = DateTimePicker1.Value.ToString

        cmd2.Parameters.AddWithValue("@end1", OleDbType.Date).Value = DateTimePicker2.Value.ToString

        Dim myreader As OleDbDataReader = cmd2.ExecuteReader

        If (myreader.Read()) Then

            MessageBox.Show(" The room reserved from: " & (myreader.GetValue("2").ToString & " to: " & (myreader.GetValue("3").ToString)))

        Else

            MessageBox.Show(" The Room not reserved before")

        End If

        conn.Close()

    End Sub

End Class