ADO.net增删改的使用

添加数据

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//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 = "n001";

//将民族名称转为名族代号
SqlConnection conn = new SqlConnection("server=.;database=mydb;user=sa;pwd=123");
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表添加数据
cmd.CommandText = "insert into Info values('"+code+"','"+name+"','"+sex+"','"+nationcode+"','"+birthday+"')";
conn.Open();
cmd.ExecuteNonQuery();
conn.Close();
Console.WriteLine("添加成功!");

Console.ReadLine();

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删除数据

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//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();

//判断该数据存不存在
SqlConnection conn = new SqlConnection("server=.;database=mydb;user=sa;pwd=123");
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=123");
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;

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修改数据

将cmd.commandtext语句改为需要update语句即可

原文地址:https://www.cnblogs.com/dreamer666/p/5794311.html