Function.cs

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

namespace Project
{
    class Function
    {
        protected SqlConnection getConnection()
        {
            SqlConnection con = new SqlConnection();
            con.ConnectionString = "Data Source=DESKTOP-IOGAUF0\\SQLEXPRESS;Initial Catalog=myHotel;Integrated Security=True";
            return con;
        }
        public DataSet getData(string query)
        {
            SqlConnection con = getConnection();
            SqlCommand cmd = new SqlCommand();
            cmd.Connection = con;
            cmd.CommandText = query;
            SqlDataAdapter da = new SqlDataAdapter(cmd);
            DataSet ds = new DataSet();
            da.Fill(ds);
            return ds;
        }
        public void setData(string query,string message)
        {
            SqlConnection con = getConnection();
            SqlCommand cmd = new SqlCommand();
            cmd.Connection = con;
            con.Open();
            cmd.CommandText = query;
            cmd.ExecuteNonQuery();
            con.Close(); 
            MessageBox.Show(" '" + message + "' ", "Success", MessageBoxButtons.OK, MessageBoxIcon.Information);
            
        }
        public SqlDataReader getForCombo(string query)
        {
            SqlConnection con = getConnection();
            SqlCommand cmd = new SqlCommand();
            cmd.Connection = con;
            con.Open();
            cmd = new SqlCommand(query, con);
            SqlDataReader sdr = cmd.ExecuteReader();
            return sdr;
        }
    }
}