2.C#实验五：ADO.NET数据库操作练习详解

　　本文作者：许前刚 博客地址：http://www.cnblogs.com/xu-qian-gang

　　周六忙了一下午，终于把C#实验五（扩充实验）：ADO.NET数据库操作练习给严格按照老师的要求给解决了，下面分享一下主要思路和代码，望同学们别笑，这个实验是ADO.NET中最基本的对数据库增删改查操作，数据访问和业务逻辑全部用代码完成，不带一点数据库绑定控件。由于写得很仓促，没有优化，里面还有很多不尽人意的地方。

注意：项目建好后需要在引用中添加System.Configuration的引用，并按实验要求建好数据库就行！
项目整体树形结构图：



登陆页面Name注释：



主窗体Name注释：



程序入口代码：文件名Program.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Windows.Forms;

namespace ADO
{
static class Program
{
/// <summary>
/// 应用程序的主入口点。
/// </summary>
[STAThread]
static void Main()
{
string dataDir = AppDomain.CurrentDomain.BaseDirectory;
if (dataDir.EndsWith(@"\bin\Release\") || dataDir.EndsWith(@"\bin\Debug\"))
{
dataDir = System.IO.Directory.GetParent(dataDir).Parent.Parent.FullName;
AppDomain.CurrentDomain.SetData("DataDirectory", dataDir);
}
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
Application.Run(new FormLogin());
}
}
}

应用程序配置文件信息：文件名App.config

 <?xml version="1.0" encoding="utf-8" ?>
<configuration>
<connectionStrings>
<add name="ShiYanFive" connectionString="Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\App_Data\Student.mdf;Integrated Security=True"/>
</connectionStrings>
</configuration>

数据访问层代码：文件名DatabaseOperation.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Configuration;
using System.Data.SqlClient;
using System.Data;

namespace ADO.App_Code.DAL
{
public static class DatabaseOperation
{
//静态只读变量，用来存取数据库连接字符串
private static readonly string constr = ConfigurationManager.ConnectionStrings["ShiYanFive"].ConnectionString;

/// <summary>
/// 用来执行带参数和不带参数仅返回所影响的行数的sql语句，如：insert，delete，update
/// </summary>
/// <param name="sql">所要执行的sql语句</param>
/// <param name="pams">sql语句中所带的参数</param>
/// <returns>返回所影响的行数</returns>
public static int ExecuteNonQuery(string sql, params SqlParameter[] pams)
{
using (SqlConnection conn = new SqlConnection(constr))
{
using (SqlCommand cmd = new SqlCommand(sql, conn))
{
if (pams!=null)
{
cmd.Parameters.AddRange(pams);
}
if (conn.State == ConnectionState.Closed)
{
conn.Open();
}
return cmd.ExecuteNonQuery();
}
}
}

/// <summary>
/// 返回一个DataTable，可以执行select语句
/// </summary>
/// <param name="sql">所要执行的sql语句</param>
/// <param name="pams">sql语句中所带的参数</param>
/// <returns>返回一个DataTable</returns>
public static DataTable ExecuteDataTable(string sql, params SqlParameter[] pams)
{
using(SqlDataAdapter adapter=new SqlDataAdapter(sql,constr))
{
if(pams!=null)
{
adapter.SelectCommand.Parameters.AddRange(pams);
}
DataTable dt=new DataTable();
adapter.Fill(dt);
return dt;
}
}
}
}

业务逻辑层代码1：文件名Login.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data.SqlClient;
using ADO.App_Code.DAL;
using System.Data;

namespace ADO.App_Code.BLL
{
class Login
{
public static int LoginForm(string username, string password)
{
string sql = "select * from Manager where username=@username and password=@password";
SqlParameter[] pams ={
new SqlParameter("@username",username),
new SqlParameter("@password",password)
};
DataTable dt = DatabaseOperation.ExecuteDataTable(sql, pams);
return dt.Rows.Count;
}
}
}
业务逻辑层代码2：StudentOperation.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data;
using ADO.App_Code.DAL;
using System.Data.SqlClient;

namespace ADO.App_Code.BLL
{
public static class StudentOperation
{
/// <summary>
/// 查询Student表中的所有数据
/// </summary>
/// <returns>返回的是一个DataTable表</returns>
public static DataTable getStudentDataTable()
{
DataTable dt = new DataTable();
string sql="select * from Student";
dt = DatabaseOperation.ExecuteDataTable(sql);
return dt;
}

/// <summary>
/// 按姓名和性别条件查询Student表中的数据
/// </summary>
/// <param name="name">姓名</param>
/// <param name="sex">性别</param>
/// <returns>返回按姓名和性别条件查询的DataTable表</returns>
public static DataTable getStudentDataTable(string name, string sex)
{
string sql = "select * from Student where studentName=@studentName and sex=@sex";
DataTable dt = new DataTable();
dt = DatabaseOperation.ExecuteDataTable(sql, new SqlParameter("@studentName", name), new SqlParameter("@sex", sex));
return dt;
}

/// <summary>
/// 按学号条件查询Student表中的数据
/// </summary>
/// <param name="studentNO">学号</param>
/// <returns>返回按学号条条件查询的DataTable表</returns>
public static DataTable getStudentDataTable(string studentNO)
{
string sql = "select * from Student where StudentNO=@StudentNO";
DataTable dt = new DataTable();
dt = DatabaseOperation.ExecuteDataTable(sql, new SqlParameter("@StudentNO", studentNO));
return dt;
}

/// <summary>
/// 向Student表中插入数据
/// </summary>
/// <param name="studentNO">学号</param>
/// <param name="name">姓名</param>
/// <param name="sex">性别</param>
/// <param name="datetime">出生日期</param>
/// <param name="department">学院</param>
/// <returns>返回插入数据后所影响的行数</returns>
public static int insertStudent(string studentNO, string name, string sex, DateTime datetime, string department)
{
string sql = "insert into Student values(@StudentNO,@studentname,@sex,@birthday,@department)";
SqlParameter[] pams ={
new SqlParameter("@StudentNO",studentNO),
new SqlParameter("@studentname",name),
new SqlParameter("@sex",sex),
new SqlParameter("@birthday",datetime),
new SqlParameter("@department",department)
};
return DatabaseOperation.ExecuteNonQuery(sql, pams);
}

/// <summary>
/// 按学号对Student表进行更新
/// </summary>
/// <param name="studentNO">学号</param>
/// <param name="name">姓名</param>
/// <param name="sex">性别</param>
/// <param name="datetime">生日</param>
/// <param name="department">学院</param>
/// <returns>返回更新后缩影响的行数</returns>
public static int updateStudent(string studentNO, string name, string sex, DateTime datetime, string department)
{
string sql = "update Student set studentName=@studentName,sex=@sex,birthday=@birthday,department=@department where StudentNO=@studentNO";
SqlParameter[] pams ={
new SqlParameter("@studentName",name),
new SqlParameter("@sex",sex),
new SqlParameter("@birthday",datetime),
new SqlParameter("@department",department),
new SqlParameter("@studentNO",studentNO),
};
return DatabaseOperation.ExecuteNonQuery(sql, pams);
}

/// <summary>
/// 按学号删除Student表中的信息
/// </summary>
/// <param name="studentNO">学号</param>
/// <returns>返回删除后所影响的行数</returns>
public static int deleteStudent(string studentNO)
{
string sql = "delete from Student where StudentNO=@StudentNO";
return DatabaseOperation.ExecuteNonQuery(sql, new SqlParameter("@StudentNO", studentNO));
}
}
}

登录窗体后台代码：文件名LoginForm.cs

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using ADO.App_Code.BLL;
using ADO.UI;

namespace ADO
{
public partial class FormLogin : Form
{
public FormLogin()
{
InitializeComponent();
}

//确定按钮事件

private void buttonQueding_Click(object sender, EventArgs e)
{
if (textBoxUserName.Text != "" && textBoxPassword.Text != "")
{
if (Login.LoginForm(textBoxUserName.Text, textBoxPassword.Text) > 0)
{
//MessageBox.Show("登陆成功！");
MainForm mainForm = new MainForm();
mainForm.Show();
this.Hide();
}
else
{
MessageBox.Show("用户名和密码错误，请重新输入。");
textBoxUserName.Text = "";
textBoxPassword.Text = "";
}
}
else
{
MessageBox.Show("用户名和密码不能为空，请重新输入。");
textBoxUserName.Text = "";
textBoxPassword.Text = "";
}
}

//取消按钮事件

private void buttonCancel_Click(object sender, EventArgs e)
{
Application.Exit();
}
}
}

主窗体后台代码：文件名MainForm.cs
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using ADO.App_Code.BLL;

namespace ADO.UI
{
public partial class MainForm : Form
{
public MainForm()
{
InitializeComponent();
}

public DataGridView DataGridViewDetails//定义dataGridViewDetails的公有属性，方便在事件函数外操作以及对dataGridViewDetails的操作方法的封装
{
get
{
return this.dataGridViewDetails;//返回私有字段dataGridViewDetails
}
}

//加载窗体时的事件

private void MainForm_Load(object sender, EventArgs e)
{
//调用getStudentTable()方法，获取Student表中的全部数据，并绑定到DataGridViewDetails
getStudentTable();

//向comboBoxSex中添加数据项集合，并设置索引为0的项为默认显示项
comboBoxSex.Items.Add("男");
comboBoxSex.Items.Add("女");
comboBoxSex.SelectedIndex = 0;

//设定单选按钮的“男”属性为默认选定
radioButtonSex1.Checked = true;
}

//查询按钮事件

private void buttonSelect_Click(object sender, EventArgs e)
{
//调用getStudentTable(string name, string sex)方法，按姓名和性别条件获取Student表中的数据信息，并绑定到DataGridViewDetails
getStudentTable(textBoxName.Text, comboBoxSex.SelectedItem.ToString());
}

//增加按钮事件

private void buttonInsert_Click(object sender, EventArgs e)
{
string studentNO = textBoxNO.Text;//获取学号
string name = textBoxName2.Text;//获取姓名
string sex;//获取性别
if (radioButtonSex1.Checked)
{
sex = radioButtonSex1.Text;
}
else
{
sex = radioButtonSex2.Text;
}
DateTime datetime = dateTimePicker1.Value;//获取出生日期
string department = textBoxDepartment.Text;//获取学院

//插入数据前查询数据库学号是否相同，因为学号是数据库Student表的主键，如果相同，则无法插入
int rows = StudentOperation.getStudentDataTable(studentNO).Rows.Count;
if (rows > 0)
{
MessageBox.Show("不能插入相同的学号信息！");
}
else
{
int row = StudentOperation.insertStudent(studentNO, name, sex, datetime, department);
if (row > 0)
{
MessageBox.Show("插入成功！");
getStudentTable();
}
else
{
MessageBox.Show("数据库操作失败！");
}
}
}

//修改按钮事件

private void buttonUpdate_Click(object sender, EventArgs e)
{
string studentNO = textBoxNO.Text;//获取学号
string name = textBoxName2.Text;//获取姓名
string sex;//获取性别
if (radioButtonSex1.Checked)
{
sex = radioButtonSex1.Text;
}
else
{
sex = radioButtonSex2.Text;
}
DateTime datetime = dateTimePicker1.Value;//获取出生日期
string department = textBoxDepartment.Text;//获取学院

if (StudentOperation.updateStudent(studentNO, name, sex, datetime, department) > 0)
{
MessageBox.Show("更新成功！");
getStudentTable();
}
else
{
MessageBox.Show("更新失败！");
}

}

//删除按钮事件

private void buttonDelete_Click(object sender, EventArgs e)
{
string studentNO = textBoxNO.Text;//获取学号
if (StudentOperation.deleteStudent(studentNO) > 0)
{
MessageBox.Show("删除成功！");
getStudentTable();
}
else
{
MessageBox.Show("删除失败！");
}
}

//dataGridView点击事件

private void dataGridViewDetails_Click(object sender, EventArgs e)
{
DataGridViewRow row = dataGridViewDetails.CurrentRow;//获取当前点击行的信息

//以下是获取当前点击行的每一列的数据信息
string studentNO = row.Cells[0].Value.ToString();
string name = row.Cells[1].Value.ToString();
string sex = row.Cells[2].Value.ToString();
DateTime datetime = Convert.ToDateTime(row.Cells[3].Value);
string department = row.Cells[4].Value.ToString();

//以下是分别把获取到的值赋值主窗体下面的每一个文本框
textBoxNO.Text = studentNO;
textBoxName2.Text = name;
if (sex=="男")
{
radioButtonSex1.Checked = true;
}
else if (sex == "女")
{
radioButtonSex2.Checked = true;
}
dateTimePicker1.Value = datetime;
textBoxDepartment.Text = department;
}

//当主窗体关闭时的事件

private void MainForm_FormClosed(object sender, FormClosedEventArgs e)
{
//当点击主窗体右上角的退出按钮时，整个程序全部退出
Application.Exit();
}

/// <summary>
/// 获取Student表中的全部数据，并绑定到DataGridViewDetails
/// </summary>
private void getStudentTable()
{
//先清除DataGridView中的原有数据
for (int i = 0; i < DataGridViewDetails.Rows.Count; i++)
{
DataGridViewDetails.Rows.Remove(DataGridViewDetails.Rows[i]);
}

//调用StudentOperation.getStudentDataTable()方法返回一个装有Student表全部信息的DataTable，然后绑定到DataGridView的数据源
DataGridViewDetails.DataSource = StudentOperation.getStudentDataTable();

//调用setDataGridViewColumnsTitle()方法设定DataGridView的每一列的标题名
setDataGridViewColumnsTitle();

//取消DataGridView的默认选中行
DataGridViewDetails.Rows[0].Selected = false;
}

/// <summary>
/// 按姓名和性别条件获取Student表中的数据信息，并绑定到DataGridViewDetails
/// </summary>
/// <param name="name">姓名</param>
/// <param name="sex">性别</param>
private void getStudentTable(string name, string sex)
{
//先清除DataGridView中的原有数据
for (int i = 0; i < DataGridViewDetails.Rows.Count; i++)
{
DataGridViewDetails.Rows.Remove(DataGridViewDetails.Rows[i]);
}

//调用StudentOperation.getStudentDataTable(name, sex)返回一个按姓名和性别查询的Student表
DataTable dt=StudentOperation.getStudentDataTable(name, sex);

//判断返回的表的行数，如果大于0，则把该表绑定到DataGridView的数据源
if (dt.Rows.Count > 0)
{
DataGridViewDetails.DataSource = dt;
setDataGridViewColumnsTitle();
}

//取消DataGridView的默认选中行
DataGridViewDetails.Rows[0].Selected = false;
}

/// <summary>
/// 设置DataGridView中列的标题
/// </summary>
private void setDataGridViewColumnsTitle()
{
DataGridViewDetails.Columns["StudentNO"].HeaderText = "学号";
DataGridViewDetails.Columns["studentName"].HeaderText = "姓名";
DataGridViewDetails.Columns["sex"].HeaderText = "性别";
DataGridViewDetails.Columns["birthday"].HeaderText = "出生日期";
DataGridViewDetails.Columns["department"].HeaderText = "学院";

//以下方式也可行
//DataGridViewDetails.Columns[0].HeaderText = "学号";
//DataGridViewDetails.Columns[1].HeaderText = "姓名";
//DataGridViewDetails.Columns[2].HeaderText = "性别";
//DataGridViewDetails.Columns[3].HeaderText = "出生日期";
//DataGridViewDetails.Columns[4].HeaderText = "学院";
}
}
}