练习

练习：
//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的话：把查到的这条数据删除
//4.当用户输入2的话：让用户输入修改的其它值，输入完成修改这条数据
//5.当用户输入3的话：让用户输入所有的列，然后保存到数据库

Console.WriteLine("请输入一个代号:");
string code = Console.ReadLine();
SqlConnection conn = new SqlConnection("server=.;database=mydb;user=sa;pwd=yue801828");
SqlCommand cmd = conn.CreateCommand();
cmd.CommandText = "select * from Car where Code=@code";
cmd.Parameters.Clear();
cmd.Parameters.AddWithValue("@code", code);
conn.Open();
SqlDataReader dr = cmd.ExecuteReader();


if (dr.HasRows)
{
while (dr.Read())
{
Console.WriteLine(dr[0] + "--" + dr[1]);
Console.WriteLine("输入1删除该数据 , 输入2修改数据,输入3添加数据");
}
int a = int.Parse(Console.ReadLine());
dr.Close();
if (a == 1)
{
cmd.CommandText = "delete from car where Code=@code";
cmd.ExecuteNonQuery();
Console.WriteLine("删除成功！");
}
else if (a == 2)
{
Console.WriteLine("请输入您要修改的数据:");
string name = Console.ReadLine();
cmd.Parameters.Clear();
cmd.Parameters.AddWithValue("@code", code);
cmd.Parameters.AddWithValue("@name", name);
cmd.CommandText = "update car set name=@name where code=@code";
cmd.ExecuteNonQuery();
Console.WriteLine("修改成功!");
}
else if (a == 3)
{
Console.WriteLine("请输入内容:");

Console.WriteLine("请输入代号");
string Code = Console.ReadLine();
Console.WriteLine("请输入名称:");
string Name = Console.ReadLine();
Console.WriteLine("请输入系列名:");
string Brand = Console.ReadLine();
Console.WriteLine("请输入日期");
string time = Console.ReadLine();
Console.WriteLine("请输入内容油耗*.**");
double oil = double.Parse(Console.ReadLine());
Console.WriteLine("请输入内容马力");
int powers = int.Parse(Console.ReadLine());
Console.WriteLine("请输入内容");
int exhaust = int.Parse(Console.ReadLine());
Console.WriteLine("请输入内容");
double price = double.Parse(Console.ReadLine());
Console.WriteLine("请输入内容");
string pic = Console.ReadLine();

cmd.CommandText = "insert into car values( @code,@name,@brand,@time,@oil,@powers,@exhaust,@price,@pic)";
cmd.Parameters.Clear();
cmd.Parameters.AddWithValue("@code", code2);
cmd.Parameters.AddWithValue("@name", name);
cmd.Parameters.AddWithValue("@brand", brand);
cmd.Parameters.AddWithValue("@time", time);
cmd.Parameters.AddWithValue("@oil", oil);
cmd.Parameters.AddWithValue("@powers", powers);
cmd.Parameters.AddWithValue("@exhaust", exhaust);
cmd.Parameters.AddWithValue("@price", price);
cmd.Parameters.AddWithValue("@pic", pic);
cmd.ExecuteNonQuery();
Console.WriteLine("添加成功！");
}

 

else
{
Console.WriteLine("输入有误");
}
}
else
{
Console.WriteLine("没有查到相应的数据");
}


conn.Close();

Console.ReadLine();

}
}
}