day 24 C# 用控制台应用程序打印数据库数据

编写一个控制台应用程序，将MySchool中Teacher表中的TeacherId、Sex、TeacherName打印出来

运行结果：

 static void Main(string[] args)
        {
            string connString = "Data Source=.;Initial Catalog=MySchool;Uid=sa;Pwd=123456;";
            SqlConnection connection = new SqlConnection(connString);

            string sql = "select TeacherId,Sex,TeacherName from Teacher";
            SqlCommand command = new SqlCommand(sql, connection);

            try
            {
                connection.Open();
                SqlDataReader dataReader = command.ExecuteReader();
                while (dataReader.Read())
                {
                    for(int i = 0; i < dataReader.FieldCount; i++)
                    {
                        Console.Write(dataReader.GetValue(i)+" ");
                       //打印读取的一列数据
                    } 
                    Console.WriteLine();    
                    //读取下一列时换行
                }
                dataReader.Close();
            }
            catch(Exception ex)
            {
                Console.WriteLine("操作数据库出错！");
                Console.WriteLine(ex.Message);
            }
            finally
            {
                connection.Close();
            }
            
        }

or 换一种方式，因为DataReader本来就是像指针一样读取一行记录，所以可以试试不用两层循环。

 static void Main(string[] args)
        {
            string connString = "Data Source=.;Initial Catalog=MySchool;User ID=sa;Pwd=12345";
            SqlConnection connection = new SqlConnection(connString);

            string sql = "select TeacherId,Sex,TeacherName from Teacher";
            SqlCommand command = new SqlCommand(sql, connection);

            try
            {
                connection.Open();
                int teacherId;
                string sex = "";
                string teacherName = "";
                SqlDataReader dataReader = command.ExecuteReader();
                while (dataReader.Read())
                {
                    teacherId = (int)dataReader["TeacherId"];
                    sex = (string)dataReader["Sex"];
                    teacherName = (string)dataReader["TeacherName"];
                    Console.WriteLine("{0},{1},{2}", teacherId,sex,teacherName);
                }
                dataReader.Close();
            }
            catch(Exception ex)
            {
                Console.WriteLine(ex.Message);
                Console.WriteLine("操作数据库出错");
            }
            finally
            {
                connection.Close();
            }
        }     

数据源MySchool在我分享的资源中可获得。