ADO.NET增删改

static void Main1(string[] args)
{
添加
造连接字符串
string connstring = "server=.;database=mydb;user=sa;pwd=100867";
造连接对象
 SqlConnection conn = new SqlConnection(connstring);
造命令对象 直接生成一个命令对象
SqlCommand cmd= conn.CreateCommand();
给一个SQL语句
cmd.CommandText = "insert into Info values('p087','李丽','true','n001','1988-2-10')";
cmd.CommandText = "delete from Info where code='p087'";
 cmd.CommandText = "update Info set name='张三' where code='p002'";
打开连接
 conn.Open();
   cmd.ExecuteNonQuery();
if (n > 0)
{
 Console.WriteLine("添加成功！");
}
else
{
 Console.WriteLine("添加失败！");
}

 conn.Close();

 Console.ReadLine();

}

让用户输入要添加的内容
Console.WriteLine("请输入要添加的代号：");
string code = Console.ReadLine();
Console.WriteLine("请输入姓名：");
string name = Console.ReadLine();
Console.WriteLine("请输入性别：");
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 = "noo1";
//将民族名称转为民族代号
SqlConnection conn = new SqlConnection("server=.;database=mydb;user=sa;pwd=100867");
SqlCommand cmd= conn.CreateCommand();
cmd.CommandText = "select code from nation where name='"+nation+"'";
conn.Open();
SqlDataReader dr= cmd.ExecuteReader();
if (dr.HasRows)
{
dr.Read();
nationcode= dr[0].ToString();
}
conn.Close();
//往INFO表中添加数据 民族表也可以添加了
cmd.CommandText = "insert into Info values('"+code+"','"+name+"','"+sex+"','"+nationcode+"','"+birthday+"')";
conn.Open();
cmd.ExecuteNonQuery();

Console.WriteLine("添加成功！");
conn.Close();

Console.ReadLine();

用户输入要删除的数据主键值
Console.WriteLine("请输入要删除的代号：");
string code = Console.ReadLine();
//先判断该数据库存不存在——根据主键值去查数据库
SqlConnection conn = new SqlConnection("server=.;database=mydb;user=sa;pwd=100867");
SqlCommand cmd= conn.CreateCommand();
cmd.CommandText = "select * from Info where code='"+code+"'";
conn.Open();
SqlDataReader dr= cmd.ExecuteReader();;

if (dr.HasRows)
{
//说明该数据存在
Console.WriteLine("查到该数据，是否要执行删除操作，如果要删除请输入：1");
int sc=Convert.ToInt32( Console.ReadLine());
if (sc == 1)
{
//删除
dr.Close();//关闭读取器
cmd.CommandText = "delete from Info where code='"+code+"'";

cmd.ExecuteNonQuery();
Console.WriteLine("删除成功！");

}
else
{
//不删除
dr.Read();
string sex= Convert.ToBoolean(dr[2])?"男":"女";
string nation = minzu(dr[3].ToString());
string str = "代号："+dr[0]+"姓名："+dr[1]+"性别："+sex+"民族:"+nation+"生日："+dr[4];

Console.WriteLine(str);

}
}
else
{
//数据不存在
Console.WriteLine("输入的代号错误！");
}

conn.Close();
Console.ReadLine();

}
static string minzu(string code)
{
string name = "";
SqlConnection conn = new SqlConnection("server=.;database=mydb;user=sa;pwd=100867");
SqlCommand cmd = conn.CreateCommand();
cmd.CommandText = "select name from nation where code='" + code + "'";
conn.Open();
SqlDataReader dr = cmd.ExecuteReader();
if (dr.HasRows)
{
dr.Read();
name = dr[0].ToString();
}
conn.Close();
return name;
}