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  • 作业

    static void Main(string[] args)
              {
                  //作业
                  //1、让用户输入一个代号,查到一条数据(car,info),并显示
                  //2、输出提示,输入1删除该数据,输入2修改数据,输入3添加数据
                  //3、当用户输入1,把查到的这条数据删除
                  //4、当用户输入2,提示输入其他值,主键不修改,输入完成,修改这项数据
                  //5、当用户输入3,提示用户输入所有的列,然后保存到数据库
      
                  string [] AR = new string[] { "code","姓名","性别","民族","生日"}; 
                  //用户输入代号
                  Console.WriteLine("请输入要查询的代号");
                  string code = Console.ReadLine();
                  
                  //造连接对象
                  SqlConnection conn = new SqlConnection("server=.;database=mydb;user=sa;pwd=diushiDEwutong0");
      
                  //造命令对象
                  SqlCommand cmd = conn.CreateCommand();
      
                  //给命令对象SQL语句
                  cmd.CommandText = "select * from Info where code=@code";
                  //防注入
                  //该变量绑定参数
                  cmd.Parameters.Clear();
                  cmd.Parameters.AddWithValue("@code",code);
                  
                  //打开连接
                  conn.Open();
      
                  SqlDataReader dr = cmd.ExecuteReader();
      
                  if (dr.HasRows)
                  {
                      while (dr.Read())
                     {
                          int i = 0;
      
                          while (i < dr.FieldCount)
                          {
                              Console.Write(AR[i] + "	");
                              i++;
                          }
                          Console.Write("
    ");
                          i = 0;
                          while (i < dr.FieldCount)
                          {
                              Console.Write(dr[i] + "	");
                             i++;
                          }
                          Console.Write("
    ");
                      }
                  }
                  else
                  {
                      Console.WriteLine("未查询到数据");
                      while (true)
                      {
                          dr.Close();
                          Console.WriteLine("请重新输入要查询的代号");
                          code = Console.ReadLine();
      
                          cmd.CommandText = "select * from Info where code=@code";
                          cmd.Parameters.Clear();
                          cmd.Parameters.AddWithValue("@code", code);
                          dr = cmd.ExecuteReader();
                          if (dr.HasRows)
                          {
                              while (dr.Read())
                              {
                                  int i = 0;
      
                                  while (i < dr.FieldCount)
                                  {
                                      Console.Write(AR[i] + "	");
                                      i++;
                                  }
                                  Console.Write("
    ");
                                  i = 0;
                                  while (i < dr.FieldCount)
                                  {
                                      Console.Write(dr[i] + "	");
                                      i++;
                                  }
                                  Console.Write("
    ");
                              }
                              break;
                          }
                         else
                         {
                             Console.WriteLine("未查询到数据");
                         }
                     }
                 }
     
     
                 while (true)
                 {
                     Console.WriteLine("输入1删除该数据,输入2修改数据,输入3添加数据,输入其他跳出程序");
                     string  s = Console.ReadLine();
                     if (s ==" 1")
                     {
                         if (dr.HasRows)
                         {
                             Console.WriteLine("确认删除请输入:1");
                             int sc = int.Parse(Console.ReadLine());
                             if (sc == 1)
                             {
                                 dr.Close();
                                 cmd.CommandText = "delete  from Info where code=@code";
                                 cmd.Parameters.Clear();
                                 cmd.Parameters.AddWithValue("@code", code);
                                 cmd.ExecuteNonQuery();
                                 Console.WriteLine("删除成功");
                             }
                             else
                             {
                                 Console.WriteLine("取消操作");
                             }
                         }
                     }
                     else if (s == "2")//修改内容
                     {
                         while (true)
                         {
                             dr.Close();
                             Console.Write("请输入要修改的列名:");
                             string str = Console.ReadLine();
                             string gai = "";
                             switch (str)
                             {
                                 case "姓名":
                                     gai = "Name";
                                     break;
                                 case "性别":
                                     gai = "Sex";
                                     break;
                                 case "民族":
                                     gai = "Nation";
                                     break;
                                 case "生日":
                                     gai = "Birthday";
                                     break;
                                 default: 
                                    Console.WriteLine("输入错误");
                                     continue;
                                     
                            }
                            if (gai == "Sex")
                             {
                                Console.Write("请输入要修改的内容:");
                                 bool sex = Console.ReadLine() == "男" ? true : false;
                                cmd.CommandText = "update Info set " + gai + "='" + sex + "' where Code=@code";
                                cmd.ExecuteNonQuery();
                             }
                             else if (gai == "Nation")
                             {
                                string nationcode = "n001";
                                 Console.Write("请输入要修改的内容:");
                                 string nation = Console.ReadLine();
                                 cmd.CommandText = "select Code from Nation where Name = '" + nation + "'";
                                dr.Close();                             dr = cmd.ExecuteReader();
                              if (dr.HasRows)
                                 {
                                     dr.Read();
                                     nationcode = dr[0].ToString();
                                 }
                                 cmd.CommandText = "update Info set " + gai + "='" + nationcode + "' where Code=@code";
                                 dr.Close();
                                 cmd.ExecuteNonQuery();
                                 }
                             else
                             {
                                 Console.Write("请输入要修改的内容:");
                                 string neirong = Console.ReadLine();
                                 cmd.CommandText = "update Info set " + gai + "='" + neirong + "' where Code=@code";
                                 cmd.ExecuteNonQuery();
                             }
                             Console.WriteLine("修改成功!");
                             Console.WriteLine("修改后的内容为:");
     
                             cmd.CommandText = "select * from Info where code=@code";
                             cmd.Parameters.Clear();
                             cmd.Parameters.AddWithValue("@code", code);
                             dr = cmd.ExecuteReader();
                             if (dr.HasRows)
                             {
                                 while (dr.Read())
                                 {
                                     int i = 0;
     
                                     while (i < dr.FieldCount)
                                    {
                                         Console.Write(AR[i] + "	");
                                         i++;
                                     }
                                     Console.Write("
    ");
                                     i = 0;
                                     while (i < dr.FieldCount)
                                     {
                                        Console.Write(dr[i] + "	");
                                         i++;
                                     }
                                     Console.Write("
    ");
                                 }
                             }
                             Console.WriteLine("是否继续修改?继续修改输入1;不修改输入任意键");
                             int b = int.Parse(Console.ReadLine());
                             if (b == 1)
                            {
                                 Console.WriteLine("继续修改");
    } else { break; } } } else if (s == "3")//添加数据 { //让用户输入要添加的内容 Console.WriteLine("请输入要添加的代号:"); code = Console.ReadLine(); Console.WriteLine("请输入姓名:"); string name = Console.ReadLine(); Console.WriteLine("请输入性别:(男或女)"); bool sex = Console.ReadLine() == "男" ? true : false; Console.WriteLine("请输入民族:"); string nation = Console.ReadLine(); Console.WriteLine("请输入生日:"); string birthday = Console.ReadLine(); string nationcode = "n001"; //将民族名称转为名族代号 cmd.CommandText = "select Code from Nation where Name = '" + nation + "'"; dr.Close(); dr = cmd.ExecuteReader(); if (dr.HasRows) { dr.Read(); nationcode = dr[0].ToString(); } //往Info表添加数据 cmd.CommandText = "insert into Info values('" + code + "','" + name + "','" + sex + "','" + nationcode + "','" + birthday + "')"; dr.Close(); cmd.ExecuteNonQuery(); Console.WriteLine("添加成功!"); Console.WriteLine("添加的内容为:"); cmd.CommandText = "select * from Info where code=@code"; cmd.Parameters.Clear(); cmd.Parameters.AddWithValue("@code", code); dr = cmd.ExecuteReader(); if (dr.HasRows) { while (dr.Read()) { int i = 0; while (i < dr.FieldCount) { Console.Write(AR[i] + " "); i++; } Console.Write(" "); i = 0; while (i < dr.FieldCount) { Console.Write(dr[i] + " "); i++; } Console.Write(" "); } } } else { Console.WriteLine("程序跳出"); break; } } conn.Close(); Console.ReadLine();
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  • 原文地址:https://www.cnblogs.com/yp11/p/5777038.html
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