① 请教各位大神,VB中怎样备份正在使用中的Access数据库
当数据库打开时是不允许用file ,如果你想可以用
Private Declare Function SHFileOperation Lib "shell32.dll " Alias "SHFileOperationA " (lpFileOp As SHFILEOPSTRUCT) As Long
还有一个API函数可以达到这个要求,好像是下面的函数:
Public Declare Function CopyFile Lib "kernel32 " Alias "CopyFileA " (ByVal lpExistingFileName As String, ByVal lpNewFileName As String, ByVal bFailIfExists As Long) As Long
可以拷贝已经打开的数据库文件。
② vb怎么备份和恢复Access数据库,最好说清楚一点,我用vs做的项目
access数据库的备份很简单,是直接整个文件备份。
把mdb直接复制到新位置改名就完成了备份,恢复的话先断开所有数据库连接,删除原有mdb文件,再把备份文件改名复制回来就行了。
③ VB.NET备份SQL数据库
using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.IO;
using System.Text;
using _5dRss.Const;
using _5dRss.lib.Data.Tool;
public partial class admin_admin_dbmanage : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
//生成备份文件列表
ListBackupFiles();
if (!Page.IsPostBack)
{
Showmsg.Visible = false;
//数据库路径
lilDBPath.Text = HttpContext.Current.Request.PhysicalApplicationPath + "App_Data\\" + ConfigurationSettings.AppSettings["DBFile"];
//新建一个 FileInfo 对象,并获得数据库文件的大小,然后转换单位为KB
FileInfo myFileInfo = new FileInfo(lilDBPath.Text);
lilDBSize.Text = Convert.ToString(myFileInfo.Length/1024) + " KB";
//如果两个参数都不为空,则继续执行
if (Request.QueryString["cmd"] != null && Request.QueryString["source"] != null)
{
//备份数据库原文件名
string sourceFileName = Request.QueryString["source"];
//如果 cmd 参数为 DelFile
if (Request.QueryString["cmd"].Equals("DelFile"))
{
//删除备份数据库文件
File.Delete(HttpContext.Current.Request.PhysicalApplicationPath + "Backup\\" + sourceFileName);
//刷新备份文件列表
ListBackupFiles();
Showmsg.Visible = true;
Showmsg.Text = "<div align='center' style='margin-bottom:8px;'><img src='images/aL.gif' style='margin-bottom:-6px;'/><span class='alertTxt'>删除备份数据库成功!</span><img src='images/aR.gif' style='margin-bottom:-6px;'/></div>";
}
//如果 cmd 参数为 Restore
if (Request.QueryString["cmd"].Equals("Restore"))
{
//用备份文件覆盖原文件
File.Copy(HttpContext.Current.Request.PhysicalApplicationPath + "Backup\\" + sourceFileName, HttpContext.Current.Request.PhysicalApplicationPath + "App_Data\\" + ConfigurationSettings.AppSettings["DBFile"], true);
//刷新备份文件列表
ListBackupFiles();
Showmsg.Visible = true;
Showmsg.Text = "<div align='center' style='margin-bottom:8px;'><img src='images/aL.gif' style='margin-bottom:-6px;'/><span class='alertTxt'>还原备份数据库成功!</span><img src='images/aR.gif' style='margin-bottom:-6px;'/></div>";
}
}
}
}
protected void lnkbtnCompactDB_Click(object sender, EventArgs e)
{
//压缩修复数据库
AccessDBtool.CompactAccessDB(SysConfig.ConnectionString, HttpContext.Current.Request.PhysicalApplicationPath + "App_Data\\" + ConfigurationSettings.AppSettings["DBFile"]);
Showmsg.Visible = true;
Showmsg.Text = "<div align='center' style='margin-bottom:8px;'><img src='images/aL.gif' style='margin-bottom:-6px;'/><span class='alertTxt'>压缩修复数据库成功!</span><img src='images/aR.gif' style='margin-bottom:-6px;'/></div>";
}
protected void lnkbtnBackupDB_Click(object sender, EventArgs e)
{
string sourceFileName = HttpContext.Current.Request.PhysicalApplicationPath + "App_Data\\" + ConfigurationSettings.AppSettings["DBFile"];
string destFileName = HttpContext.Current.Request.PhysicalApplicationPath + "Backup\\" + "Backup_";
destFileName += DateTime.Now.ToString("yyyyMMddHHmmss");
destFileName += ".mbk";
//将数据库文件Copy到Backup目录,如果有重名文件就覆盖原文件
File.Copy(sourceFileName, destFileName, true);
//生成备份文件列表
ListBackupFiles();
Showmsg.Visible = true;
Showmsg.Text = "<div align='center' style='margin-bottom:8px;'><img src='images/aL.gif' style='margin-bottom:-6px;'/><span class='alertTxt'>备份数据库成功!</span><img src='images/aR.gif' style='margin-bottom:-6px;'/></div>";
}
/// <summary>
/// 生成备份文件列表
/// </summary>
/// <returns>文件列表,文件详细信息及操作选项的HTML代码</returns>
public void ListBackupFiles()
{
//如果目录不存在则创建次目录
if (!Directory.Exists(HttpContext.Current.Request.PhysicalApplicationPath + "Backup\\"))
Directory.CreateDirectory(HttpContext.Current.Request.PhysicalApplicationPath + "Backup\\");
DirectoryInfo mydir = new DirectoryInfo(HttpContext.Current.Request.PhysicalApplicationPath + "Backup\\");
StringBuilder sb = new StringBuilder();
foreach (FileInfo f in mydir.GetFiles())
{
sb.Append("<a href='backup/" + f.Name + "' target='_blank'><img border='0' src='images/mdb.gif' style='margin:4px 3px -3px 0px'/>" + f.Name + "</a> <a href='?cmd=DelFile&source=" + f.Name + "' title='删除备份文件'>删除</a> | <a href='?cmd=Restore&source=" + f.Name + "' title='删除备份文件'>还原数据库</a> | " + f.Length/1024 + " KB | " + f.CreationTime + "<br />");
}
lilBackupFileList.Text = sb.ToString();
}
}
把下面这句换成你的数据库地址:
//数据库路径
// lilDBPath.Text = HttpContext.Current.Request.PhysicalApplicationPath + "App_Data\\" + ConfigurationSettings.AppSettings["DBFile"];