/// MBD compact method (c) 2004 Alexander Youmashev
/// !!IMPORTANT!!
/// !make sure there＇s no open connections
/// to your db before calling this method!
/// !!IMPORTANT!!
/// 
/// connection string to your db
/// FULL name
/// of an MDB file you want to compress.
public static void CompactAccessDB(string connectionString, string mdwfilename)
{
    object[] oParams;

    //create an inctance of a Jet Replication Object
    object objJRO =
    Activator.CreateInstance(Type.GetTypeFromProgID("JRO.JetEngine"));

    //filling Parameters array
    //cnahge "Jet OLEDB:Engine Type=5" to an appropriate value
    // or leave it as is if you db is JET4X format (access 2000,2002)
    //(yes, jetengine5 is for JET4X, no misprint here)

    oParams = new object[] { 
connectionString,
"Provider=Microsoft.Jet.OLEDB.4.0;Data" + 
" Source=C:\\tempdb.mdb;Jet OLEDB:Engine Type=5"};

    //invoke a CompactDatabase method of a JRO object
    //pass Parameters array

    objJRO.GetType().InvokeMember("CompactDatabase",
    System.Reflection.BindingFlags.InvokeMethod,
    null,
    objJRO,
    oParams);

    //database is compacted now
    //to a new file C:\\tempdb.mdw
    //let＇s copy it over an old one and delete it

    System.IO.File.Delete(mdwfilename);
    System.IO.File.Move("C:\\tempdb.mdb", mdwfilename);
    //clean up (just in case)
    System.Runtime.InteropServices.Marshal.ReleaseComObject(objJRO);
    objJRO = null;
}

using System;
using System.IO;
using ADOX; //该命名空间包含创建ACCESS的类(方法)--解决方案 ==> 引用 ==> 添加引用 ==> 游览找到.dll
using JRO; //该命名空间包含压缩ACCESS的类(方法)

public class Access
{
    ///根据指定的文件名称创建ACCESS数据库
    ///mdbPath:要创件的ACCESS绝对路径
    public void Create(string mdbPath)
    {
        if (File.Exists(mdbPath)) //检查数据库是否已存在
        {
            throw new Exception("目标数据库已存在,无法创建");
        }
        // 可以加上密码,这样创建后的数据库必须输入密码后才能打开
        mdbPath = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + mdbPath;
        // 创建一个CatalogClass对象的实例,
        ADOX.CatalogClass cat = new ADOX.CatalogClass();
        // 使用CatalogClass对象的Create方法创建ACCESS数据库
        cat.Create(mdbPath);
    }

    ///压缩修复ACCESS数据库,mdbPath为数据库绝对路径
    public void Compact(string mdbPath)
    {
        if (!File.Exists(mdbPath)) //检查数据库是否已存在
        {
            throw new Exception("目标数据库不存在,无法压缩");
        }
        //声明临时数据库的名称
        string temp = DateTime.Now.Year.ToString();
        temp += DateTime.Now.Month.ToString();
        temp += DateTime.Now.Day.ToString();
        temp += DateTime.Now.Hour.ToString();
        temp += DateTime.Now.Minute.ToString();
        temp += DateTime.Now.Second.ToString() + ".bak";
        temp = mdbPath.Substring(0, mdbPath.LastIndexOf("\\") + 1) + temp;
        //定义临时数据库的连接字符串
        temp2 = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + temp;
        //定义目标数据库的连接字符串
        mdbPath2 = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + mdbPath;
        //创建一个JetEngineClass对象的实例
        JRO.JetEngineClass jt = new JRO.JetEngineClass();
        //使用JetEngineClass对象的CompactDatabase方法压缩修复数据库
        jt.CompactDatabase(mdbPath2, temp2);
        //拷贝临时数据库到目标数据库(覆盖)
        File.Copy(temp, mdbPath, true);
        //最后删除临时数据库
        File.Delete(temp);
    }

    /// 备份数据库,mdb1,源数据库绝对路径; mdb2: 目标数据库绝对路径 
    public void Backup(string mdb1, string mdb2)
    {
        if (!File.Exists(mdb1))
        {
            throw new Exception("源数据库不存在");
        }
        try
        {
            File.Copy(mdb1, mdb2, true);
        }
        catch (IOException ixp)
        {
            throw new Exception(ixp.ToString());
        }
    }

    ///恢复数据库,mdb1为备份数据库绝对路径,mdb2为当前数据库绝对路径
    public void Recover(string mdb1, string mdb2)
    {
        if (!File.Exists(mdb1))
        {
            throw new Exception("备份数据库不存在");
        }
        try
        {
            File.Copy(mdb1, mdb2, true);
        }
        catch (IOException ixp)
        {
            throw new Exception(ixp.ToString());
        }
    }