使用Using System.Data.OleDb; 连接数据库,又一种动态绑定GridView显示数据。

本文介绍如何在ASP.NET应用程序中配置SQL Server数据库连接字符串,并演示使用OleDb进行数据查询的具体实现方法。

1.在Web.Config内有

<appSettings >

    <add key="SQLConnectionString" value="Provider=sqloledb;data source=~/SQLEXPRESS;initial catalog=WebSiteTest;User ID=sa;Password= ***;persist security info=False;" />
  
 </appSettings> 

2.在.cs文件中

using System.Data;
using System.Data.OleDb;

.........

 string strSql = "select b.jdcode ,a.序号,a.flag, a.教材名称,b.bookname,a.作者,b.author,a.出版社,b.publish,a.版本,b.edition,a.ISBN ,b.ISBN as jdISBN,a.价格,b.price from  TempImportData1 as a left join JdData as b on 1=1 " + strSqlCheck + " where a.flag ='0' order by b.jdcode desc";
  
            string strconn2= System.Configuration.ConfigurationManager.AppSettings["SQLConnectionString"].ToString();
           
       

            OleDbConnection myConnection3 = new OleDbConnection(strconn2);

      
            //这段程序可以成功连接,不同于用微软的类库 Database db = DatabaseFactory.CreateDatabase();
            OleDbCommand commselect1 = new OleDbCommand(strSql, myConnection3);
            myConnection3.Open();
            OleDbDataReader dr1 = commselect1.ExecuteReader();
            GridView1.DataSource = dr1;
            GridView1.DataBind();
            dr1.Close();
            commselect1.Dispose();

.........

using System; using System.IO; using System.Text.RegularExpressions; using System.Windows.Forms; using Microsoft.Win32; namespace MRU { public partial class FormMRU : Form { public FormMRU() { #region InitializeComponent(); ListView listViewMRU = new ListView(); listViewMRU.Dock = DockStyle.Fill; listViewMRU.HeaderStyle = ColumnHeaderStyle.None; // 隐藏列标题。 listViewMRU.View = View.Details; // 详细信息。 listViewMRU.CheckBoxes = true; // 显示复选框。 listViewMRU.Scrollable = false; // 隐藏滚动条。 listViewMRU.ShowGroups = true; // 分组显示项。 listViewMRU.BeginUpdate(); ListViewGroup pro = listViewMRU.Groups.Add("profile", "profile"); listViewMRU.Items.Add(Environment.GetFolderPath(Environment.SpecialFolder.Recent)).Group = pro; listViewMRU.Items.Add(Environment.GetFolderPath(Environment.SpecialFolder.Cookies)).Group = pro; listViewMRU.Items.Add(Path.GetTempPath()).Group = pro; listViewMRU.Items.Add(Environment.GetFolderPath(Environment.SpecialFolder.History)).Group = pro; listViewMRU.Items.Add(Environment.GetFolderPath(Environment.SpecialFolder.InternetCache)).Group = pro; ListViewGroup reg = listViewMRU.Groups.Add("regedit", "regedit"); listViewMRU.Items.Add(@"HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\TypedURLs").Group = reg; listViewMRU.Items.Add(@"HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\RunMRU").Group = reg; listViewMRU.Items.Add(@"HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\ComDlg32").Group = reg; listViewMRU.Items.Add(@"HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Applets\Paint").Group = reg; listViewMRU.Items.Add(@"HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Applets\Wordpad").Group = reg; ColumnHeader column = listViewMRU.Columns.Add(""); column.AutoResize(ColumnHeaderAutoResizeStyle.ColumnContent); // 自动调整列宽。 listViewMRU.EndUpdate(); listViewMRU.ItemChecked += new ItemCheckedEventHandler(listViewMRU_ItemChecked); this.Controls.Add(listViewMRU); this.ClientSize = new System.Drawing.Size(column.Width + 8, 260); this.Text = Environment.UserName; this.AutoSizeMode = AutoSizeMode.GrowAndShrink; // 禁用手动调整大小。 this.SizeGripStyle = SizeGripStyle.Hide; // 隐藏调整大小手柄。 this.StartPosition = FormStartPosition.CenterScreen; // 在桌面居中显示。 #endregion } #region ListView_ItemChecked private void listViewMRU_ItemChecked(object sender, ItemCheckedEventArgs e) { if (!e.Item.Checked) return; DirectoryInfo dir = new DirectoryInfo(e.Item.Text); switch (e.Item.Index) { case 0: case 1: foreach (FileInfo info in dir.GetFiles()) { if (Regex.IsMatch(info.Extension, @".(dat|ini)", RegexOptions.IgnoreCase)) // 指定不区分大小写的匹配。 continue; this.Text = info.Name; info.Delete(); } break; case 2: foreach (FileSystemInfo info in dir.GetFileSystemInfos()) { try { if (info is FileInfo) info.Delete(); else (info as DirectoryInfo).Delete(true); } catch { continue; } finally { this.Text = info.Name; } } break; case 3: System.Diagnostics.Process.Start(e.Item.Text); break; case 4: foreach (FileInfo info in dir.GetFiles("*.*", SearchOption.AllDirectories)) { if (Regex.IsMatch(info.Extension, @".(dat|ini)", RegexOptions.IgnoreCase)) // 指定不区分大小写的匹配。 continue; try { info.Delete(); } catch { continue; } finally { this.Text = info.Name; } } break; case 5: using (RegistryKey subKey = Registry.CurrentUser.CreateSubKey(@"Software\Microsoft\Internet Explorer\TypedURLs")) { foreach (string mru in subKey.GetValueNames()) { subKey.DeleteValue(mru); } } break; case 6: using (RegistryKey subKey = Registry.CurrentUser.CreateSubKey(@"Software\Microsoft\Windows\CurrentVersion\Explorer\RunMRU")) { foreach (string mru in subKey.GetValueNames()) { subKey.DeleteValue(mru); } } break; case 7: using (RegistryKey subKey = Registry.CurrentUser.CreateSubKey(@"Software\Microsoft\Windows\CurrentVersion\Explorer\ComDlg32")) { foreach (string mru in subKey.GetSubKeyNames()) { subKey.DeleteSubKeyTree(mru); } } break; case 8: using (RegistryKey subKey = Registry.CurrentUser.CreateSubKey(@"Software\Microsoft\Windows\CurrentVersion\Applets\Paint\Recent File List")) { foreach (string mru in subKey.GetValueNames()) { subKey.DeleteValue(mru); } } break; case 9: using (RegistryKey subKey = Registry.CurrentUser.CreateSubKey(@"Software\Microsoft\Windows\CurrentVersion\Applets\Wordpad\Recent File List")) { foreach (string mru in subKey.GetValueNames()) { subKey.DeleteValue(mru); } } break; } this.Text = Environment.UserName; } #endregion } }using System; using System.IO; using System.Text.RegularExpressions; using System.Windows.Forms; using Microsoft.Win32; namespace MRU { public partial class FormMRU : Form { public FormMRU() { #region InitializeComponent(); ListView listViewMRU = new ListView(); listViewMRU.Dock = DockStyle.Fill; listViewMRU.HeaderStyle = ColumnHeaderStyle.None; // 隐藏列标题。 listViewMRU.View = View.Details; // 详细信息。 listViewMRU.CheckBoxes = true; // 显示复选框。 listViewMRU.Scrollable = false; // 隐藏滚动条。 listViewMRU.ShowGroups = true; // 分组显示项。 listViewMRU.BeginUpdate(); ListViewGroup pro = listViewMRU.Groups.Add("profile", "profile"); listViewMRU.Items.Add(Environment.GetFolderPath(Environment.SpecialFolder.Recent)).Group = pro; listViewMRU.Items.Add(Environment.GetFolderPath(Environment.SpecialFolder.Cookies)).Group = pro; listViewMRU.Items.Add(Path.GetTempPath()).Group = pro; listViewMRU.Items.Add(Environment.GetFolderPath(Environment.SpecialFolder.History)).Group = pro; listViewMRU.Items.Add(Environment.GetFolderPath(Environment.SpecialFolder.InternetCache)).Group = pro; ListViewGroup reg = listViewMRU.Groups.Add("regedit", "regedit"); listViewMRU.Items.Add(@"HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\TypedURLs").Group = reg; listViewMRU.Items.Add(@"HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\RunMRU").Group = reg; listViewMRU.Items.Add(@"HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\ComDlg32").Group = reg; listViewMRU.Items.Add(@"HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Applets\Paint").Group = reg; listViewMRU.Items.Add(@"HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Applets\Wordpad").Group = reg; ColumnHeader column = listViewMRU.Columns.Add(""); column.AutoResize(ColumnHeaderAutoResizeStyle.ColumnContent); // 自动调整列宽。 listViewMRU.EndUpdate(); listViewMRU.ItemChecked += new ItemCheckedEventHandler(listViewMRU_ItemChecked); this.Controls.Add(listViewMRU); this.ClientSize = new System.Drawing.Size(column.Width + 8, 260); this.Text = Environment.UserName; this.AutoSizeMode = AutoSizeMode.GrowAndShrink; // 禁用手动调整大小。 this.SizeGripStyle = SizeGripStyle.Hide; // 隐藏调整大小手柄。 this.StartPosition = FormStartPosition.CenterScreen; // 在桌面居中显示。 #endregion } #region ListView_ItemChecked private void listViewMRU_ItemChecked(object sender, ItemCheckedEventArgs e) { if (!e.Item.Checked) return; DirectoryInfo dir = new DirectoryInfo(e.Item.Text); switch (e.Item.Index) { case 0: case 1: foreach (FileInfo info in dir.GetFiles()) { if (Regex.IsMatch(info.Extension, @".(dat|ini)", RegexOptions.IgnoreCase)) // 指定不区分大小写的匹配。 continue; this.Text = info.Name; info.Delete(); } break; case 2: foreach (FileSystemInfo info in dir.GetFileSystemInfos()) { try { if (info is FileInfo) info.Delete(); else (info as DirectoryInfo).Delete(true); } catch { continue; } finally { this.Text = info.Name; } } break; case 3: System.Diagnostics.Process.Start(e.Item.Text); break; case 4: foreach (FileInfo info in dir.GetFiles("*.*", SearchOption.AllDirectories)) { if (Regex.IsMatch(info.Extension, @".(dat|ini)", RegexOptions.IgnoreCase)) // 指定不区分大小写的匹配。 continue; try { info.Delete(); } catch { continue; } finally { this.Text = info.Name; } } break; case 5: using (RegistryKey subKey = Registry.CurrentUser.CreateSubKey(@"Software\Microsoft\Internet Explorer\TypedURLs")) { foreach (string mru in subKey.GetValueNames()) { subKey.DeleteValue(mru); } } break; case 6: using (RegistryKey subKey = Registry.CurrentUser.CreateSubKey(@"Software\Microsoft\Windows\CurrentVersion\Explorer\RunMRU")) { foreach (string mru in subKey.GetValueNames()) { subKey.DeleteValue(mru); } } break; case 7: using (RegistryKey subKey = Registry.CurrentUser.CreateSubKey(@"Software\Microsoft\Windows\CurrentVersion\Explorer\ComDlg32")) { foreach (string mru in subKey.GetSubKeyNames()) { subKey.DeleteSubKeyTree(mru); } } break; case 8: using (RegistryKey subKey = Registry.CurrentUser.CreateSubKey(@"Software\Microsoft\Windows\CurrentVersion\Applets\Paint\Recent File List")) { foreach (string mru in subKey.GetValueNames()) { subKey.DeleteValue(mru); } } break; case 9: using (RegistryKey subKey = Registry.CurrentUser.CreateSubKey(@"Software\Microsoft\Windows\CurrentVersion\Applets\Wordpad\Recent File List")) { foreach (string mru in subKey.GetValueNames()) { subKey.DeleteValue(mru); } } break; } this.Text = Environment.UserName; } #endregion } }
`using System.Data;` 语句用于引入 `System.Data` 命名空间,该命名空间提供了表示 ADO.NET 结构的类,用于在应用程序和数据源之间进行数据交互。 ### 用途 - **数据访问基础**:`System.Data` 命名空间是 ADO.NET 的核心命名空间,提供了数据访问的基础类和接口,如 `DataSet`、`DataTable`、`DataRow` 等,用于在内存中存储和操作数据。 - **数据库通信**:虽然具体的数据库通信类(如 `SqlConnection`、`SqlCommand` 等)位于其他命名空间(如 `System.Data.SqlClient`),但 `System.Data` 为这些类提供了通用的接口和数据结构,使得不同数据库的访问具有一致性 [^1]。 - **数据绑定**:支持数据绑定机制,允许将数据绑定到各种控件上,实现数据的可视化展示。 ### 使用场景 - **数据库操作**:在进行数据库操作时,`System.Data` 中的类可以用于创建和管理数据集、数据表等,方便对数据进行增删改查操作。例如,使用 `DataSet` 可以一次性从数据库中获取多个表的数据,并在内存中进行处理 [^3]。 ```csharp using System; using System.Data; using System.Data.SqlClient; class Program { static void Main() { string connectionString = "YourConnectionString"; using (SqlConnection connection = new SqlConnection(connectionString)) { SqlCommand command = new SqlCommand("SELECT * FROM YourTable", connection); SqlDataAdapter adapter = new SqlDataAdapter(command); DataSet dataSet = new DataSet(); adapter.Fill(dataSet, "YourTable"); DataTable table = dataSet.Tables["YourTable"]; foreach (DataRow row in table.Rows) { Console.WriteLine(row["ColumnName"]); } } } } ``` - **数据验证和转换**:可以使用 `System.Data` 中的类对数据进行验证和转换,确保数据的有效性和一致性。 - **数据缓存**:将数据存储在 `DataSet` 或 `DataTable` 中,可以实现数据的缓存,减少对数据库的频繁访问,提高应用程序的性能。
评论
成就一亿技术人!
拼手气红包6.0元
还能输入1000个字符
 
红包 添加红包
表情包 插入表情
 条评论被折叠 查看
添加红包

请填写红包祝福语或标题

红包个数最小为10个

红包金额最低5元

当前余额3.43前往充值 >
需支付:10.00
成就一亿技术人!
领取后你会自动成为博主和红包主的粉丝 规则
hope_wisdom
发出的红包
实付
使用余额支付
点击重新获取
扫码支付
钱包余额 0

抵扣说明:

1.余额是钱包充值的虚拟货币,按照1:1的比例进行支付金额的抵扣。
2.余额无法直接购买下载,可以购买VIP、付费专栏及课程。

余额充值