【C#】【平时作业】习题-11-ADO.NET

选择题

1.下列ASP.NET语句（B）正确地创建了一个与mySQL数据库和服务器的连接。

A.SqlConnection con1 = new Connection(“Data Source = localhost; Integrated Security = SSPI; Initial Catalog = myDB”);

B. MySqlConnection con1 = new MySqlConnection (“Server=localhost;Database = myDB;Uid=root;Pwd=;”);

C.SqlConnection con1 = new SqlConnection(Data Source = localhost; Integrated Security = SSPI; Initial Catalog = myDB);

D.SqlConnection con1 = new OleDbConnection(“Data Source = localhost; Integrated Security = SSPI; Initial Catalog = myDB”);

2.在ADO.NET中，对于MySqlCommand对象的ExecuteNonQuery()方法和MySqlDataAdapter对象的Fill ()方法，下面叙述错误的是（C）

A.insert、update、delete等操作的mySql语句主要用ExecuteNonQuery()方法来执行；

B.ExecuteNonQuery()方法返回执行mySql语句所影响的行数。

C.Select操作的mySql语句只能由Fill ()方法来执行；

D.Fill ()方法返回一个DataSet对象；

简述并举例说明

什么是ADO.NET？

在NET编程环境中优先使用的数据访问接口

什么是连接字符串？

连接字符串，是一组被格式化的键值对：

它告诉ADO.NET数据源在哪里

需要什么样的数据格式

提供什么样的访问信任级别

以及其他任何包括连接的相关信息。

connection对象的作用？

Connection(连接对象)：与数据源建立连接。

commmand对象的作用？

Command(命令对象)：对数据源执行SQL命令并返回结果。

dataAdapter对象的作用？

DataAdapter(适配器对象)：对数据源执行操作并返回结果，在DataSet与数据源之间建立通信，将数据源中的数据写入

DataReader对象的作用？

DataReader(数据流对象)：取数据源的数据，只允许对将数据源以只读、顺向的方式查看其中所存储的数据。其常用于检索大量数据，DataReader对象还是一种非常节省资源的数据对象。

DataSet对象的作用？

DataSet(数据集对象)：内存中的数据库，是数据表的集合，它可以包含任意多个数据表。

程序设计

//字段
        private string _account;
        private string _name;
        private string _usertype;
        private string _password;
        private string _vip;
        private string _garde;
        private string _amount;
        private string _age;
        private string _hobby;
        private string _department;
        private const string CONSTR = "Server=127.0.0.1;Database=studentsinfo;UserId=root;Password=qq2686485465;";
//属性
        public string Account { get => _account; set => _account = value; }
        public string Name { get => _name; set => _name = value; }
        public string Usertype { get => _usertype; set => _usertype = value; }
        public string Password { get => _password; set => _password = value; }
        public string Vip { get => _vip; set => _vip = value; }
        public string Garde { get => _garde; set => _garde = value; }
        public string Amount { get => _amount; set => _amount = value; }
        public string Age { get => _age; set => _age = value; }
        public string Hobby { get => _hobby; set => _hobby = value; }
        public string Department { get => _department; set => _department = value; }

1. 已知本机上的MySql数据库studentsinfo中有学生表.请给HandleStudent类添加成员函数:public bool HandleLogin((string studentAccount, string studentPwd) 该方法可检验学生登录时的信息是否有效。
   
   提示：学生表中字段类型自定，但需满足数据的合理性。

   //验证登录
           /// <summary>
           /// 登录验证
           /// </summary>
           /// <param name="studentAccount">账号</param>
           /// <param name="studentPwd">密码</param>
           /// <returns>Boolean 验证成功返回真，否则返回假</returns>
           public static bool HandleLogin(string studentAccount, string studentPwd)
           {
               //对参数进行处理验证
               if (Equals(studentAccount.Trim(), "") || Equals(studentPwd.Trim(), "")) return false;
               //连接数据库
               MySqlConnection con = HandleConnection();
               //打开数据库
               con.Open();
               //参数化拼接字符串
               string sql = "Select*from students where `account` = @Account AND `password` = @Password";
               //创建命令对象
               MySqlCommand cmd = new MySqlCommand(sql, con);
               //指定参数
               cmd.Parameters.Add(new MySqlParameter("@Account",studentAccount));
               cmd.Parameters.Add(new MySqlParameter("@Password", studentPwd));
               //执行
               MySqlDataReader dr = cmd.ExecuteReader();
               //判断
               if (dr.Read())
               {
                   con.Close();
                   return true;
               }
               else
               {
                   con.Close();
                   return false;
               }
   
           }
   

2. 已知本机上的MySql数据库studentsinfo中有学生表students,请给HandleStudent类添加成员函数public static int HandleAddStudents<T>(HandleStudent student) 该方法可添加一位学生的信息到数据表中。
   
   提示：学生表中字段类型自定，但需满足数据的合理性。

  /// <summary>
        /// 根据主键判断 是否存在学生
        /// </summary>
        /// <param name="key"></param>
        /// <returns>boolea 存在返回真，不存在返回假</returns>
        public static bool HandleStudentIsIn(string key)
        {
            //对参数进行处理验证
            if (Equals(key.Trim(), ""))  return false;
            //连接数据库
            MySqlConnection con = HandleConnection();
            //打开数据库
            con.Open();
            //参数化拼接字符串
            string sql = "Select*from students where `account` = @Account";
            //创建命令对象
            MySqlCommand cmd = new MySqlCommand(sql, con);
            //指定参数
            cmd.Parameters.Add(new MySqlParameter("@Account", key));
            //执行
            MySqlDataReader dr = cmd.ExecuteReader();
            //判断
            if (dr.Read())
            {
                con.Close();
                return true;
            }
            else
            {
                con.Close();
                return false;
            }
        }

 /// <summary>
        /// 添加学生
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="student"></param>
        /// <returns>int型 操作影响的行数</returns>
        public static int HandleAddStudents<T>(HandleStudent student)
        {
            MySqlConnection con = HandleConnection();
            con.Open();
            //判断学生是否存在,信息是否完善
            if (HandleStudentIsIn(student.Account) || Equals(student.Account,"") || Equals(student.Name, "" ) || Equals(student.Password, "") || Equals(student.Usertype, "")) return 0;
            //添加学生信息
            string sql = "INSERT INTO students(`account`,`name`,`usertype`,`password`,`vip`,`garde`,`amount`,`age`,`hobby`,`department`)" +
                "VALUES" +
                "(@Account,@Name,@UserType,@Password,1,0,0,0,'IT','OMTPC')";
            MySqlCommand cmd = new MySqlCommand(sql, con);
            cmd.Parameters.Add(new MySqlParameter("@Account",student.Account));
            cmd.Parameters.Add(new MySqlParameter("@Name", student.Name));
            cmd.Parameters.Add(new MySqlParameter("@UserType", student.Usertype));
            cmd.Parameters.Add(new MySqlParameter("@Password", student.Password));
            int rows = cmd.ExecuteNonQuery();
            con.Close();
            return rows;
        }

项目完整代码

Form1.cs 点击查看代码

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace WindowsFormsApp1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            if (HandleStudent.HandleLogin("202171031022", "1234566789"))
            {
                MessageBox.Show("登录成功！");
            }
            else
            {
                MessageBox.Show("登录失败！");
            }
        }

        private void button2_Click(object sender, EventArgs e)
        {
            if (HandleStudent.HandleLogin("000000000", "000000000"))
            {
                MessageBox.Show("登录成功！");
            }
            else
            {
                MessageBox.Show("登录失败！");
            }
        }

        private void button3_Click(object sender, EventArgs e)
        {
            Random seed = new Random();
            string xuehao = seed.Next(100, 999).ToString()+ seed.Next(1000, 9999).ToString() + seed.Next(100, 999).ToString() + seed.Next(10, 99).ToString();
            string mima = seed.Next(100, 999).ToString() + seed.Next(1000, 9999).ToString() + seed.Next(100, 999).ToString() + seed.Next(10, 99).ToString();
            string dianhua = seed.Next(100, 999).ToString() + seed.Next(100, 999).ToString() + seed.Next(100, 999).ToString() + seed.Next(10, 99).ToString();
            HandleStudent pep = new HandleStudent(xuehao, mima,"张三",dianhua);
            MessageBox.Show("该操作影响行数为："+HandleStudent.HandleAddStudents<HandleStudent>(pep).ToString());
        }

        private void button4_Click(object sender, EventArgs e)
        {
            Random seed = new Random();
            string xuehao = seed.Next(100, 999).ToString() + seed.Next(1000, 9999).ToString() + seed.Next(100, 999).ToString() + seed.Next(10, 99).ToString();
            string mima = seed.Next(100, 999).ToString() + seed.Next(1000, 9999).ToString() + seed.Next(100, 999).ToString() + seed.Next(10, 99).ToString();
            string dianhua = seed.Next(100, 999).ToString() + seed.Next(100, 999).ToString() + seed.Next(100, 999).ToString() + seed.Next(10, 99).ToString();
            HandleStudent pep = new HandleStudent("", "", "", "");
            MessageBox.Show("该操作影响行数为：" + HandleStudent.HandleAddStudents<HandleStudent>(pep).ToString());
        }
    }
}

HandleStudent.cs - 点击查看代码

using MySql.Data.MySqlClient;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace WindowsFormsApp1
{
    class HandleStudent
    {
        //字段
        private string _account;
        private string _name;
        private string _usertype;
        private string _password;
        private string _vip;
        private string _garde;
        private string _amount;
        private string _age;
        private string _hobby;
        private string _department;
        private const string CONSTR = "Server=127.0.0.1;Database=studentsinfo;UserId=root;Password=qq2686485465;";
        //属性
        public string Account { get => _account; set => _account = value; }
        public string Name { get => _name; set => _name = value; }
        public string Usertype { get => _usertype; set => _usertype = value; }
        public string Password { get => _password; set => _password = value; }
        public string Vip { get => _vip; set => _vip = value; }
        public string Garde { get => _garde; set => _garde = value; }
        public string Amount { get => _amount; set => _amount = value; }
        public string Age { get => _age; set => _age = value; }
        public string Hobby { get => _hobby; set => _hobby = value; }
        public string Department { get => _department; set => _department = value; }

        //构造函数
        public HandleStudent() { }
        public HandleStudent(string studentAccount, string studentPasswd)
        {
            _account = studentAccount;
            _password = studentPasswd;
        }
        public HandleStudent(string studentAccount, string studentPasswd, string stdentName, string studentTel)
        {
            _account = studentAccount;
            _password = studentPasswd;
            _name = stdentName;
            _usertype = studentTel;
        }
        //操作方法
        /// <summary>
        /// 连接数据库
        /// </summary>
        /// <returns>MySqlConnection 数据库连接对象</returns>
        public static MySqlConnection HandleConnection() {
            MySqlConnection con = new MySqlConnection(CONSTR);
            return con;
        }
        /// <summary>
        /// 根据主键判断 是否存在学生
        /// </summary>
        /// <param name="key"></param>
        /// <returns>boolea 存在返回真，不存在返回假</returns>
        public static bool HandleStudentIsIn(string key)
        {
            //对参数进行处理验证
            if (Equals(key.Trim(), ""))  return false;
            //连接数据库
            MySqlConnection con = HandleConnection();
            //打开数据库
            con.Open();
            //参数化拼接字符串
            string sql = "Select*from students where `account` = @Account";
            //创建命令对象
            MySqlCommand cmd = new MySqlCommand(sql, con);
            //指定参数
            cmd.Parameters.Add(new MySqlParameter("@Account", key));
            //执行
            MySqlDataReader dr = cmd.ExecuteReader();
            //判断
            if (dr.Read())
            {
                con.Close();
                return true;
            }
            else
            {
                con.Close();
                return false;
            }
        }
        /// <summary>
        /// 登录验证
        /// </summary>
        /// <param name="studentAccount">账号</param>
        /// <param name="studentPwd">密码</param>
        /// <returns>Boolean 验证成功返回真，否则返回假</returns>
        public static bool HandleLogin(string studentAccount, string studentPwd)
        {
            //对参数进行处理验证
            if (Equals(studentAccount.Trim(), "") || Equals(studentPwd.Trim(), "")) return false;
            //连接数据库
            MySqlConnection con = HandleConnection();
            //打开数据库
            con.Open();
            //参数化拼接字符串
            string sql = "Select*from students where `account` = @Account AND `password` = @Password";
            //创建命令对象
            MySqlCommand cmd = new MySqlCommand(sql, con);
            //指定参数
            cmd.Parameters.Add(new MySqlParameter("@Account",studentAccount));
            cmd.Parameters.Add(new MySqlParameter("@Password", studentPwd));
            //执行
            MySqlDataReader dr = cmd.ExecuteReader();
            //判断
            if (dr.Read())
            {
                con.Close();
                return true;
            }
            else
            {
                con.Close();
                return false;
            }

        }
        /// <summary>
        /// 添加学生
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="student"></param>
        /// <returns>int型 操作影响的行数</returns>
        public static int HandleAddStudents<T>(HandleStudent student)
        {
            MySqlConnection con = HandleConnection();
            con.Open();
            //判断学生是否存在,信息是否完善
            if (HandleStudentIsIn(student.Account) || Equals(student.Account,"") || Equals(student.Name, "" ) || Equals(student.Password, "") || Equals(student.Usertype, "")) return 0;
            //添加学生信息
            string sql = "INSERT INTO students(`account`,`name`,`usertype`,`password`,`vip`,`garde`,`amount`,`age`,`hobby`,`department`)" +
                "VALUES" +
                "(@Account,@Name,@UserType,@Password,1,0,0,0,'IT','OMTPC')";
            MySqlCommand cmd = new MySqlCommand(sql, con);
            cmd.Parameters.Add(new MySqlParameter("@Account",student.Account));
            cmd.Parameters.Add(new MySqlParameter("@Name", student.Name));
            cmd.Parameters.Add(new MySqlParameter("@UserType", student.Usertype));
            cmd.Parameters.Add(new MySqlParameter("@Password", student.Password));
            int rows = cmd.ExecuteNonQuery();
            con.Close();
            return rows;
        }

    }
}