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 System.Data;using System.Data.SqlClient;namespace WindowsFormsApplication1{  public partial class Form1 : Form  {    public Form1()    {      InitializeComponent();    }    //查詢    private void button1_Click(object sender, EventArgs e)    {      string MyConn = "server=127.0.0.1;uid=sa;pwd=123654;database=libbook;Trusted_Connection=no";//定義數據庫連接參數      SqlConnection MyConnection = new SqlConnection(MyConn);//定義一個數據連接實例      SqlCommand MyCommand = new SqlCommand("SELECT * FROM 圖書借閱", MyConnection); //定義一個數據庫操作指令      SqlDataAdapter SelectAdapter = new SqlDataAdapter();//定義一個數據適配器      SelectAdapter.SelectCommand = MyCommand;//定義數據適配器的操作指令      DataSet MyDataSet = new DataSet();//定義一個數據集      MyConnection.Open();//打開數據庫連接      SelectAdapter.SelectCommand.ExecuteNonQuery();//執行數據庫查詢指令      MyConnection.Close();//關閉數據庫      SelectAdapter.Fill(MyDataSet);//填充數據集      DataGrid1.DataSource = MyDataSet.Tables[0];      //DataGrid1.DataBind();//將數據表格用數據集中的數據填充    }    //添加    private void button2_Click(object sender, EventArgs e)    {      string MyConn = "server=127.0.0.1;uid=sa;pwd=123654;database=libbook;Trusted_Connection=no";      SqlConnection MyConnection = new SqlConnection(MyConn);      string MyInsert = "insert into 圖書借閱 (圖書編號,讀者編號,續借次數) values ('" + Convert.ToString(textBox2.Text) + "','" +        Convert.ToString(textBox3.Text)+ "','"+Convert.ToInt32(textBox4.Text)+ "')";      SqlCommand MyCommand = new SqlCommand(MyInsert, MyConnection);      try//異常處理      {        MyConnection.Open();        MyCommand.ExecuteNonQuery();        MyConnection.Close();      }      catch (Exception ex)      {        MessageBox.Show(ex.Message);      }    }    //更新    private void button3_Click(object sender, EventArgs e)    {      string MyConn = "server=127.0.0.1;uid=sa;pwd=123654;database=libbook;Trusted_Connection=no";      SqlConnection MyConnection = new SqlConnection(MyConn);      string MyUpdate = "Update 圖書借閱 set 操作員='" + textBox2.Text + "'" + " where 借閱編號=" + "'" + textBox1.Text + "'";      SqlCommand MyCommand = new SqlCommand(MyUpdate, MyConnection);      try      {        MyConnection.Open();        MyCommand.ExecuteNonQuery();        MyConnection.Close();        textBox1.Text = "";      }      catch (Exception ex)      {        MessageBox.Show(ex.Message);      }    }    //刪除    private void button4_Click(object sender, EventArgs e)    {      string MyConn = "server=127.0.0.1;uid=sa;pwd=123654;database=libbook;Trusted_Connection=no";      SqlConnection MyConnection = new SqlConnection(MyConn);      string MyDelete = "Delete from 圖書借閱 where 借閱編號=" + textBox1.Text;      SqlCommand MyCommand = new SqlCommand(MyDelete, MyConnection);      try      {        MyConnection.Open();        MyCommand.ExecuteNonQuery();        MyConnection.Close();        textBox1.Text = "";      }      catch (Exception ex)      {        MessageBox.Show(ex.Message);      }    }  }}