如果是SQLSERVER，在WEB程序中可以连接数据源，直接用CREATE DATABASE创建。而Access可以用ADOX创建。

自己有个创建数据库的Helper.cs（部分代码）：

/// <summary>
/// 创建SqlServer数据库
/// </summary>
/// <param name="dbName">数据库名</param>
/// <param name="dbPath">数据库存放路径："d:\\cs\\"</param>
/// <returns></returns>
public static bool CreateSqlServerDb(string dbName, string dbPath)
{
    string dbDir = dbPath;
    string createStr = "Data Source=" + StrHelper.GetItemValueFromConnStr(connStr, "Source") + ";Initial Catalog='master';Persist Security Info=True;User ID=" + StrHelper.GetItemValueFromConnStr(connStr, "ID") + ";Password=" + StrHelper.GetItemValueFromConnStr(connStr, "Password");
    String createDb;
    SqlConnection createConn = new SqlConnection(createStr);

    createDb = "CREATE DATABASE " + dbName + " ON PRIMARY " +
        "(NAME = " + dbName + ", " +
        "FILENAME = '" + dbDir + dbName + ".mdf', " +
        "SIZE = 3MB, MAXSIZE = 10MB, FILEGROWTH = 10%) " +
        "LOG ON (NAME = " + dbName + "_Log, " +
        "FILENAME = '" + dbDir + dbName + "_Log.ldf', " +
        "SIZE = 1MB, " +
        "MAXSIZE = 5MB, " +
        "FILEGROWTH = 10%)";
    SqlCommand createCmd = new SqlCommand(createDb, createConn);
    try
    {
        createConn.Open();
        createCmd.ExecuteNonQuery();
    }
    catch (System.Exception)
    {
        return false;
    }
    finally
    {
        if (createConn.State == ConnectionState.Open)
        {
            createConn.Close();
        }
    }
    return true;
}
#endregion

Access：

。。。

ADOX.CatalogClass buildDb = new ADOX.CatalogClass();
                buildDb.Create("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + dbPath + dbName + ";" + "Jet OLEDB:Engine Type=5");

                ADODB.Connection cn = new ADODB.Connection();//建立链接
                cn.Open("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + dbPath + dbName, null, null, -1);
                buildDb.ActiveConnection = cn;

                ADOX.Table tableTemp = null;//创建临时表

。。。