public insert() { Console.Write("请输入姓名："); String name = Console.ReadLine(); Console.Write("请输入年龄："); String age = Console.ReadLine(); Console.Write("请输入地址："); String add = Console.ReadLine(); SqlConnection conn = new SqlConnection(@"server=.;database=mydb;uid=sa;pwd=sa"); //第一种占位符的使用方式 SqlCommand cmd = conn.CreateCommand(); cmd.CommandText = "insert into login values(@username,@userage,@useradd)"; cmd.Parameters.AddWithValue("@username", name); cmd.Parameters.AddWithValue("@userage", age); cmd.Parameters.AddWithValue("@useradd", add); //第二种占位符的使用方式 String sql = string.Format("insert into login values('{0}',{1},'{2}')", name, age, add); SqlCommand cmd = new SqlCommand(sql, conn); try { conn.Open(); int i = cmd.ExecuteNonQuery(); if (i > 0) { Console.WriteLine("插入数据成功"); } cmd.Dispose(); conn.Close(); } finally { conn.Close(); }}