例题

using System.Data.SqlClient;      引用命名空间

namespace homework0705
{
class Program
{
static void Main(string[] args)
{
Console.WriteLine("==============================信息展示===============================");
Console.WriteLine("
");
SqlConnection conn = new SqlConnection("server=.;database=Data0551;user=sa;pwd=123;");
SqlCommand cmd = conn.CreateCommand();
conn.Open();
cmd.CommandText = "select * from Users";
SqlDataReader dr = cmd.ExecuteReader();
Console.WriteLine("编号 用户名 密码 昵称 性别 生日 民族 ");
while (dr.Read())
{
Console.WriteLine(dr["Ucode"] + " " + dr["UserName"] + " " + dr["PassWord"] + " " + dr["NickName"] + " " + (Convert.ToBoolean(dr["Sex"]) ? "男" : "女") + " " + (Convert.ToDateTime(dr["Birthday"]).ToString("yyyy年MM月dd日")) + " " + dr["Nation"]);
}
conn.Close();


Console.WriteLine("
");

 

 

 


bool has = false;


int Mling = 0;
int n = 0;
while (true)
{
while (true)
{
Console.Write("请输入您要执行的操作(添加：1，修改：2，删除：3)：");
string str = Console.ReadLine();
//int n = int.Parse(str);
if (int.TryParse(str, out n))
{
if (n >= 1 && n <= 3)
{
Mling = n;
break;
}
else
{
Console.WriteLine("输入错误，请重新输入正确的操作命令！");
}
}

}
if (Mling == 1)
{
string Ucode = "";
conn.Open();
cmd.CommandText = "select * from Users order by Ucode desc";
SqlDataReader dr1 = cmd.ExecuteReader();
dr1.Read();
Ucode = dr1["Ucode"].ToString();
int u = Convert.ToInt32(Ucode.Substring(1));
u++;
Ucode = "U" + u.ToString("000");
conn.Close();
Console.Write("您的编号是：" + Ucode);

string UserName;
while (true)
{
Console.Write("请输入用户名：");
UserName = Console.ReadLine();
if (UserName == "")
{
Console.WriteLine("用户名不能为空，请重新输入！");
}
else { break; }
}

string PassWord;
while (true)
{
Console.Write("请输入密码：");
PassWord = Console.ReadLine();
if (PassWord == "")
{
Console.WriteLine("密码不能为空，请重新输入！");
}
else if (PassWord.Length < 4)
{
Console.WriteLine("密码的长度不能小于4，请重新输入！");
}
else if (PassWord.Length >= 4)
{
break;
}
}

string NickName;
while (true)
{
Console.Write("请输入昵称：");
NickName = Console.ReadLine();
if (NickName == "")
{
Console.WriteLine("用户昵称不能为空，请重新输入！");
}
else { break; }
}

string Sex;
while (true)
{
Console.Write("请输入性别（男/女）：");
Sex = Console.ReadLine();
if (Sex == "男")
{
Convert.ToBoolean(Sex = "true");
break;
}
else if (Sex == "女")
{
Convert.ToBoolean(Sex = "false");
break;
}
else { Console.WriteLine("输入错误，请重新输入！"); }
}

Console.Write("请输入生日（格式：2000-1-1）：");
string Birthday = Console.ReadLine();

string Nation;
while (true)
{
Console.Write("请输入民族（汉族 满族 藏族 彝族）：");
Nation = Console.ReadLine();
if (Nation == "汉族")
{
Nation = "N001";
break;
}
else if (Nation == "满族")
{
Nation = "N002";
break;
}
else if (Nation == "藏族")
{
Nation = "N003";
break;
}
else if (Nation == "彝族")
{
Nation = "N004";
break;
}
else { Console.WriteLine("您输入的民族无效，请重新输入！"); }
}
int count = 0;

conn.Open();
cmd.CommandText = "insert into Users values (@a,@b,@c,@d,@e,@f,@g)";
cmd.Parameters.Clear();
cmd.Parameters.AddWithValue("@a", Ucode);
cmd.Parameters.AddWithValue("@b", UserName);
cmd.Parameters.AddWithValue("@c", PassWord);
cmd.Parameters.AddWithValue("@d", NickName);
cmd.Parameters.AddWithValue("@e", Sex);
cmd.Parameters.AddWithValue("@f", Birthday);
cmd.Parameters.AddWithValue("@g", Nation);

count = cmd.ExecuteNonQuery();
conn.Close();


if (count > 0)
{
Console.WriteLine("添加成功！");

}
else
{
Console.WriteLine("添加失败！");

}
}

if (Mling == 2)
{
//int state = 0;
string Ucode = "";
while (true)
{
Console.Write("请输入您要修改的信息编号：");
Ucode = Console.ReadLine();
if (Ucode == "")
{
Console.WriteLine("编号不能为空，请重新输入！");
}
else if (Ucode.Substring(1).Length == 3)
{
break;
}
else
{
Console.Write("请输入正确的编号！");
}
}
conn.Open();
cmd.CommandText = "select * from Users where Ucode=@a";
cmd.Parameters.Clear();
cmd.Parameters.AddWithValue("@a", Ucode);
SqlDataReader dr1 = cmd.ExecuteReader();
if (dr1.HasRows)
{
Console.WriteLine("已查询到此信息");
//state = 1;
has = true;
}
else
{
Console.WriteLine("未查到此用户信息");
break;
}
conn.Close();

if (has)
{
string UserName;
while (true)
{
Console.Write("请输入新的用户名：");
UserName = Console.ReadLine();
if (UserName == "")
{
Console.WriteLine("用户名不能为空，请重新输入！");
}
else { break; }
}
string PassWord;
while (true)
{
Console.Write("请输入新的密码：");
PassWord = Console.ReadLine();
if (PassWord == "")
{
Console.WriteLine("密码不能为空，请重新输入！");
}
else if (PassWord.Length < 4)
{
Console.WriteLine("密码的长度不能小于4，请重新输入！");
}
else if (PassWord.Length >= 4)
{
break;
}
}
string NickName;
while (true)
{
Console.Write("请输入新的昵称：");
NickName = Console.ReadLine();
if (NickName == "")
{
Console.WriteLine("用户昵称不能为空，请重新输入！");
}
else { break; }
}
string Sex;
while (true)
{
Console.Write("请输入新的性别（男/女）：");
Sex = Console.ReadLine();
if (Sex == "男")
{
Convert.ToBoolean(Sex = "true");
break;
}
else if (Sex == "女")
{
Convert.ToBoolean(Sex = "false");
break;
}
else { Console.WriteLine("输入错误，请重新输入！"); }
}

Console.Write("请输入新的生日（格式：2000-1-1）：");
string Birthday = Console.ReadLine();

string Nation;
while (true)
{
Console.Write("请输入新的民族（汉族 满族 藏族 彝族）：");
Nation = Console.ReadLine();
if (Nation == "汉族")
{
Nation = "N001";
break;
}
else if (Nation == "满族")
{
Nation = "N002";
break;
}
else if (Nation == "藏族")
{
Nation = "N003";
break;
}
else if (Nation == "彝族")
{
Nation = "N004";
break;
}
else { Console.WriteLine("您输入的民族无效，请重新输入！"); }
}
conn.Open();
cmd.CommandText = "update Users set UserName =@a,PassWord =@b,NickName =@c,Sex =@d,Birthday =@e,Nation=@f where Ucode ='" + Ucode + "'";
cmd.Parameters.Clear();
cmd.Parameters.AddWithValue("@a", UserName);
cmd.Parameters.AddWithValue("@b", PassWord);
cmd.Parameters.AddWithValue("@c", NickName);
cmd.Parameters.AddWithValue("@d", Sex);
cmd.Parameters.AddWithValue("@e", Birthday);
cmd.Parameters.AddWithValue("@f", Nation);
int count = cmd.ExecuteNonQuery();
conn.Close();

if (count > 0)
Console.WriteLine("修改成功！");
else
{
Console.WriteLine("修改失败！");
break;
}
}
}
if (Mling == 3)
{
//int state = 0;
string Ucode = "";
while (true)
{
Console.Write("请输入您要删除的信息编号：");
Ucode = Console.ReadLine();
if (Ucode == "")
{
Console.WriteLine("编号不能为空，请重新输入！");
}
else if (Ucode.Substring(1).Length == 3)
{
break;
}
else
{
Console.WriteLine("编号错误，请输入正确的编号！");
}
}
conn.Open();
cmd.CommandText = "select * from Users where Ucode =@a";
cmd.Parameters.Clear();
cmd.Parameters.AddWithValue("@a", Ucode);
SqlDataReader dr1 = cmd.ExecuteReader();
if (dr1.HasRows)
{
//state = 1;
has = true;

}
else
{
Console.WriteLine("未查到此用户信息!");
//state = 2;
}
conn.Close();
//if (state == 2)
//{
// break;
//}
if (has)
{
string str = "";
while (true)
{
Console.Write("已查询到此信息，是否确定删除？（Y/N）");
str = Console.ReadLine();
if (str == "Y")
{
conn.Open();
cmd.CommandText = "delete from Users where Ucode=@a";
cmd.Parameters.Clear();
cmd.Parameters.AddWithValue("@a", Ucode);
int count = cmd.ExecuteNonQuery();
conn.Close();
if (count > 0)
{
Console.WriteLine("删除成功！");
}
break;
}
else if (str == "N")
{
Console.WriteLine("已取消删除！");
break;
}
else
{
Console.WriteLine("输入错误，请按照提示输入！（Y/N）");
}
}
}
else { break; }
}
}
Console.ReadLine();
}
}
}