ado完整的增删改查操作

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

namespace ConsoleApplication10
{
    class Program
    {
        static void Main(string[] args)
        {
            //建立数据连接
            SqlConnection conn = new SqlConnection("server=.;database=data0425;user=sa;pwd=123;");
            //建立数据命令
            SqlCommand cmd = conn.CreateCommand();
            while (true)
            {
                Console.WriteLine("========================学生信息============================");
                cmd.CommandText = "select * from student";
                conn.Open();
                SqlDataReader dr = cmd.ExecuteReader();
                if (dr.HasRows)
                {
                    while (dr.Read())
                    {
                        Console.WriteLine
                        ("学号：" + dr["code"] +
                        "    姓名：" + dr["name"] +
                        "    性别：" + ((bool)dr["sex"] ? "男" : "女") +
                        "    生日：" + (((DateTime)dr["bithday"]).ToString("yyyy年MM月dd日")) +
                        "    分数：" + (((decimal)dr["score"]).ToString("#.##")) + "");
                    }
                }
                conn.Close();
                Console.WriteLine("============================================================");
                //提示用户操作
                Console.Write("请输入您想要的操作（1=添加，2=修改，3=删除，4=结束操作）：");
                string caozuo = Console.ReadLine();
                if (caozuo == "1")
                {
                    Console.WriteLine("正在为您进行添加操作!");
                    Console.WriteLine("**************************添加******************************");
                    Console.Write("请输入您要添加的学号：");
                    string scode = Console.ReadLine();
                    Console.Write("请输入您要添加的姓名：");
                    string sname = Console.ReadLine();
                    //判断用户输入是否正确
                    bool ssex;
                    while (true)
                    {
                        Console.Write("请输入您要添加的性别(男或女)：");
                        string shuru = Console.ReadLine();
                        if (shuru == "男")
                        {
                            ssex = true;
                            break;
                        }
                        else if (shuru == "女")
                        {
                            ssex = false;
                            break;
                        }
                        else
                        {
                            Console.Clear();
                            Console.WriteLine("您的输入性别有误！只能输入男或者女！请重新输入！");
                        }
                    }

                    DateTime sbirthday;
                    while (true)
                    {
                        Console.Write("请输入您要添加的生日：");
                        try
                        {
                            DateTime dt = Convert.ToDateTime(Console.ReadLine());
                            sbirthday = dt;
                            break;
                        }
                        catch
                        {
                            Console.WriteLine("您输入的日期格式不正确，年月日请用-隔开！");
                        }
                    }

                    decimal sscore;
                    while (true)
                    {
                        Console.Write("请输入您要添加的分数（0~100）：");
                        try
                        {
                            decimal a = Convert.ToDecimal(Console.ReadLine());
                            if (a >= 0 && a <= 100)
                            {
                                sscore = a;
                                break;
                            }
                            else
                            {
                                Console.WriteLine("您的输入的分数有误！请输入0~100之间的数字！");
                            }
                        }
                        catch
                        {
                            Console.WriteLine("您输入的分数有误！请输入数字格式！");
                        }
                    }

                    cmd.CommandText = "insert into student values(‘" + scode + "‘,‘" + sname + "‘,‘" + ssex + "‘,‘" + sbirthday + "‘," + sscore + ")";
                    try
                    {
                        conn.Open();
                        cmd.ExecuteNonQuery();
                        conn.Close();
                        Console.Clear();
                        Console.WriteLine("添加成功！");
                    }
                    catch
                    {
                        Console.WriteLine("连接数据库失败！请重新连接！");

                    }
                }
                else if (caozuo == "2")
                {
                    Console.WriteLine("正在为您进行修改操作!");
                    Console.WriteLine("**************************修改******************************");
                    bool hastu = false;
                    while (true)
                    {
                        Console.Write("请您输入要修改的学号：");
                        string scode = Console.ReadLine();
                        cmd.CommandText = "select * from student where code=‘" + scode + "‘";
                        conn.Open();
                        SqlDataReader dr1 = cmd.ExecuteReader();
                        if (dr1.HasRows)
                        {
                            hastu = true;
                        }
                        else
                        {
                            hastu = false;
                        }
                        conn.Close();
                        if (hastu)
                        {
                            Console.WriteLine("已查询到此学生，请进行操作！");

                            Console.Write("请输入您要修改的姓名：");
                            string sname = Console.ReadLine();

                            bool ssex;
                            while (true)
                            {
                                Console.Write("请输入您要修改的性别(男或女)：");
                                string shuru = Console.ReadLine();
                                if (shuru == "男")
                                {
                                    ssex = true;
                                    break;
                                }
                                else if (shuru == "女")
                                {
                                    ssex = false;
                                    break;
                                }
                                else
                                {
                                    Console.WriteLine("您的输入性别有误！只能输入男或者女！请重新输入！");
                                }
                            }

                            DateTime sbirthday;
                            while (true)
                            {
                                Console.Write("请输入您要修改的生日：");
                                try
                                {
                                    DateTime dt = Convert.ToDateTime(Console.ReadLine());
                                    sbirthday = dt;
                                    break;
                                }
                                catch
                                {
                                    Console.WriteLine("您输入的日期格式不正确，年月日请用-隔开！");
                                }
                            }

                            decimal sscore;
                            while (true)
                            {
                                Console.Write("请输入您要修改的分数（0~100）：");
                                try
                                {
                                    decimal a = Convert.ToDecimal(Console.ReadLine());
                                    if (a >= 0 && a <= 100)
                                    {
                                        sscore = a;
                                        break;
                                    }
                                    else
                                    {
                                        Console.WriteLine("您的输入的分数有误！请输入0~100之间的数字！");
                                    }
                                }
                                catch
                                {
                                    Console.WriteLine("您输入的分数有误！请输入数字格式！");
                                }
                            }

                            cmd.CommandText = "update student set name=@xingming,sex=@xingbie,bithday=@shengri,score=@fenshu where code=@bianhao";
                            cmd.Parameters.Clear();
                            //防字符串攻击
                            cmd.Parameters.Add("@xingming", sname);
                            cmd.Parameters.Add("@xingbie", ssex);
                            cmd.Parameters.Add("@shengri", sbirthday);
                            cmd.Parameters.Add("@fenshu", sscore);
                            cmd.Parameters.Add("@bianhao", scode);
                            try
                            {
                                conn.Open();
                                cmd.ExecuteNonQuery();
                                Console.Clear();
                                Console.WriteLine("修改成功！");
                                conn.Close();
                                break;
                            }
                            catch
                            {
                                conn.Close();
                                Console.WriteLine("连接数据库失败！请重新连接！");

                            }
                        }
                        else
                        {
                            Console.Clear();
                            Console.WriteLine("查无此学生信息！请重新输入！");
                        }
                    }
                }
                else if (caozuo == "3")
                {
                    Console.WriteLine("正在为您进行删除操作!");
                    Console.WriteLine("**************************删除******************************");
                    bool hastu = false;
                    while (true)
                    {
                        Console.Write("请您输入要删除的学生编号：");
                        string scode = Console.ReadLine();
                        cmd.CommandText = "select * from student where code=‘" + scode + "‘";
                        conn.Open();
                        SqlDataReader dr1 = cmd.ExecuteReader();
                        if (dr1.HasRows)
                        {
                            hastu = true;
                        }
                        else
                        {
                            hastu = false;
                        }
                        conn.Close();
                        if (hastu)
                        {
                            Console.WriteLine("已经查询到该学生信息！正在进行删除操作！");
                            cmd.CommandText = "delete from student where code=‘" + scode + "‘";
                            try
                            {
                                conn.Open();
                                cmd.ExecuteNonQuery();
                                Console.Clear();
                                Console.WriteLine("删除成功！");
                                conn.Close();
                                break;
                            }
                            catch
                            {
                                conn.Close();
                                Console.WriteLine("连接数据库失败！请重新连接！");
                            }
                        }
                        else
                        {
                            Console.WriteLine("查询不到此学生信息！请重新输入！");
                        }
                    }
                }
                else if (caozuo == "4")
                {
                    Console.WriteLine("退出操作！请摁回车键！");
                    break;
                }
                else
                {
                    Console.WriteLine("您的输入有误！请重新输入");
                }

            }

            Console.ReadLine();
        }
    }
}