using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Data.SqlClient;
namespace ConsoleApplication1
{
    class Program
    {
        private const string ent = @"Data Source=.;Initial Catalog=MySchool;Integrated Security=True; User ID=ru;Password=12";

        static void Main(string[] args)
        {
            Program Q = new Program();
            Q.su();
           
            string names = "Admin";
            string pass = "0";
            string strMsg = "資訊";
            bool b = Q.CheckUserInfo( names, pass,ref strMsg);
            if (b)
            {
                Console.WriteLine(strMsg);

            }
            else
            {
                Console.WriteLine(strMsg);
            }
            Console.ReadLine();

        }

        public void su()
        {
            Console.WriteLine("請輸入使用者名稱:");
            string name = Console.ReadLine();
            Console.WriteLine("請輸入密碼:");
          int pass =int.Parse(Console.ReadLine());
          if (pass != 000)
          {
              Console.WriteLine("登入失敗");
          }
          else
          {
              Console.WriteLine("登入成功");
              cg();
          }

        }

        public void cg()
        {
            Console.WriteLine("==========請選擇操作鍵==========");
            Console.WriteLine("1.統計學生人數");
            Console.WriteLine("2.檢視學生名單");
            Console.WriteLine("3.按學號查詢學生姓名");
            Console.WriteLine("4.按姓名查詢學生資訊");
            Console.WriteLine("5.修改學生出生日期");
            Console.WriteLine("6.刪除學生記錄");
            Console.WriteLine("7.新增年紀記錄");
            Console.WriteLine("8.退出");
            Console.WriteLine("================================");
          int m=int.Parse(Console.ReadLine());
            switch(m){
                case 1:
                 Console.WriteLine("在校學生人數:"+qun());
                    break;
                case 2:

                    break;
                case 3:

                    break;
            case 4:

                    break;
                case 5:
                    
                    break;
                case 6:

                    break;
                case 7:

                    break;
                case 8:
                    Console.WriteLine("退出!");
                    break;
                default:
                    Console.WriteLine("輸入錯誤,請重新輸入:");
                    break;
                

            }



        }

        public int qun()
        {
            SqlConnection tuy = new SqlConnection(ent);
            try
            {
                tuy.Open();
                string re = "select count(StudentNo) from dbo.Student  ";
                    SqlCommand  du=new SqlCommand(re,tuy);
                int we=(int)du.ExecuteScalar();
                return we;
            }
            catch(Exception ex)
            {
                Console.WriteLine(ex.Message);
                return -1;
            }
            finally
            {
           tuy.Close(); 
          Console.WriteLine("關閉語句");


            }

 
        }

            public bool CheckUserInfo(string names,string pass,ref string strMsg )
            {

            SqlConnection connection = new SqlConnection(ent);
            try
            {

                connection.Open();
                string rr = "select COUNT(*)as 總數 from [MySchool].[dbo].[Admin] where LoginId='" + names + "'and LoginPwd='" + pass + "'";
               
                Console.WriteLine("開啟資料庫連線");
                SqlCommand comm = new SqlCommand(rr, connection);
                int ww = (int)comm.ExecuteScalar();              
                Console.WriteLine("開啟"+ww+"連線");
                if (ww != 1)
                {    
                    strMsg = "輸入無效";
                    return false;
                }
                else
                {
                    return true;
                }
            }
            catch (Exception ex)
            {
                
                Console.WriteLine("出現異常:" + ex.Message);
                Console.WriteLine("出現了問題");
                strMsg = "發生異常";
                return false;
            }
            finally
            {
            connection.Close();
            Console.WriteLine("關閉資料庫連線成功");

            }
          
  
          
        }
 
       
    }
}