knowledge Base

Codd's Rules

2008-06-10T10:07:00.000-07:00

Codd's 12 rules are a set of thirteen rules (numbered zero to twelve) proposed by Edgar Frank Codd , a pioneer of the relational model for databases, designed to define what is required from a database management system in order for it to be considered relational.

These rules were defined by Codd in a paper published in 1985. They specify what a relational database must support in order to be relational. These rules have been considerably extended in reference[2].

Rule 0 : Rule Zero for RDBMS

"For any system that is advertised as, or claimed to be, a relational database management system, that system must be able to manage databases entirely through its relational capabilities, no matter what additional capabilities the system may support." (Codd, 1990)

For a system to qualify as a relational database management system (RDMS), that system must use its relational facilities (exclusively) to manage the database.

Rule 1 : The information Rule.

"All information in a relational data base is represented explicitly at the logical level and in exactly one way - by values in tables."

Everything within the database exists in tables and is accessed via table access routines.

Rule 2 : Guaranteed access Rule.

"Each and every datum (atomic value) in a relational data base is guaranteed to be logically accessible by resorting to a combination of table name, primary key value and column name."

To access any data-item you specify which column within which table it exists, there is no reading of characters 10 to 20 of a 255 byte string.

Rule 3 : Systematic treatment of null values.

"Null values (distinct from the empty character string or a string of blank characters and distinct from zero or any other number) are supported in fully relational DBMS for representing missing information and inapplicable information in a systematic way, independent of data type."

If data does not exist or does not apply then a value of NULL is applied, this is understood by the RDBMS as meaning non-applicable data.

Rule 4 : Dynamic on-line catalog based on the relational model.

"The data base description is represented at the logical level in the same way as-ordinary data, so that authorized users can apply the same relational language to its interrogation as they apply to the regular data."

The Data Dictionary is held within the RDBMS, thus there is no-need for off-line volumes to tell you the structure of the database.

Rule 5 : Comprehensive data sub-language Rule.

"A relational system may support several languages and various modes of terminal use (for example, the fill-in-the-blanks mode). However, there must be at least one language whose statements are expressible, per some well-defined syntax, as character strings and that is comprehensive in supporting all the following items

Data Definition
View Definition
Data Manipulation (Interactive and by program).
Integrity Constraints
Authorization."

Every RDBMS should provide a language to allow the user to query the contents of the RDBMS and also manipulate the contents of the RDBMS.

Rule 6 : .View updating Rule

"All views that are theoretically updatable are also updatable by the system."

Not only can the user modify data, but so can the RDBMS when the user is not logged-in.

Rule 7 : High-level insert, update and delete.

"The capability of handling a base relation or a derived relation as a single operand applies not only to the retrieval of data but also to the insertion, update and deletion of data."

The user should be able to modify several tables by modifying the view to which they act as base tables.

Rule 8 : Physical data independence.

"Application programs and terminal activities remain logically unimpaired whenever any changes are made in either storage representations or access methods."

The user should not be aware of where or upon which media data-files are stored

Rule 9 : Logical data independence.

"Application programs and terminal activities remain logically unimpaired when information-preserving changes of any kind that theoretically permit un-impairment are made to the base tables."

User programs and the user should not be aware of any changes to the structure of the tables (such as the addition of extra columns).

Rule 10 : Integrity independence.

"Integrity constraints specific to a particular relational data base must be definable in the relational data sub-language and storable in the catalog, not in the application programs."

If a column only accepts certain values, then it is the RDBMS which enforces these constraints and not the user program, this means that an invalid value can never be entered into this column, whilst if the constraints were enforced via programs there is always a chance that a buggy program might allow incorrect values into the system.

Rule 11 : Distribution independence.

"A relational DBMS has distribution independence."

The RDBMS may spread across more than one system and across several networks, however to the end-user the tables should appear no different to those that are local.

Rule 12 : Non-subversion Rule.

"If a relational system has a low-level (single-record-at-a-time) language, that low level cannot be used to subvert or bypass the integrity Rules and constraints expressed in the higher level relational language (multiple-records-at-a-time)."

The RDBMS should prevent users from accessing the data without going through the Oracle or MSSQL data-read functions.

Note:

1) In Codd 1990, Codd extended the 12 rules to 18 to include rules on catalog, data types (domains), authorisation etc.

2) In Rule 5 Codd stated that an RDBMS required a Query Language, however Codd does not explicitly state that SQL should be the query tool, just that there should be a tool, and many of the initial products had their own tools, Oracle had UFI (User Friendly Interface), Ingres had QUEL (QUery Execution Language) and the never released DB1 had a language called sequel, the acronym SQL is often pronounced such as it was sequel that provided the core functionality to SQL.

Even when the vendors eventually all started offering SQL the flavours were/are all radically different and contained wildly varying syntax. This situation was somewhat resolved in the late 80's when ANSI brought out their first definition of the SQL syntax.

This has since been upgraded to version 2 and now all vendors offer a standard core SQL, however ANSI SQL is somewhat limited and thus all RDBMS providers offer extensions to SQL which may differ from vendor to vendor.

File Extension List

2008-06-06T12:50:00.000-07:00

File extension list contains the list of file extensions. The file extension list contain basic information: the extension, the name of the program it works with and the company that makes the program. Not all extensions have all of the data.

ile extentsion list is very big so i created a PDF file of extension list and uploaded to rapidshare.com. you can download it from link below. if for some reason link is broken comment on this post i will reupload the PDF File.

File Size: 90 KB
Download Link :
File Extension.pdf


Note:- File extension list is not complete in itself there is a possibility that some of the file extensions are not present in this list. It is also possible that some of file extension present in this list may not be used nowadays.

Windows Shortcuts

2008-06-02T07:22:00.000-07:00

ALT+- (ALT+hyphen) Displays the Multiple Document Interface (MDI) child window's System menu

ALT+ENTER View properties for the selected item

ALT+ESC Cycle through items in the order they were opened

ALT+F4 Close the active item, or quit the active program

ALT+SPACEBAR Display the System menu for the active window

ALT+TAB Switch between open items

ALT+Underlined letter Display the corresponding menu

CTRL+A Select all

CTRL+B Bold

CTRL+C Copy

CTRL+I Italics

CTRL+O Open an item

CTRL+U Underline

CTRL+V Paste

CTRL+X Cut

CTRL+Z Undo

CTRL+F4 Close the active document

CTRL while dragging Copy selected item

CTRL+SHIFT while dragging Create shortcut to selected item

CTRL+RIGHT ARROW Move the insertion point to the beginning of the next word

CTRL+LEFT ARROW Move the insertion point to the beginning of the previous word

CTRL+DOWN ARROW Move the insertion point to the beginning of the next paragraph

CTRL+UP ARROW Move the insertion point to the beginning of the previous paragraph

CTRL+ESC Display the Start menu

ESC Cancel the current task

BACKSPACE View the folder one level up in My Computer or Windows Explorer

F1 Displays Help

F2 Rename selected item

F3 Search for a file or folder

F4 Display the Address bar list in My Computer or Windows Explorer

F5 Refresh the active window

F6 Cycle through screen elements in a window or on the desktop

F10 Activate the menu bar in the active program

SHIFT+DELETE Delete selected item permanently without placing the item in the Recycle Bin

SHIFT+F10 Display the shortcut menu for the selected item

SHIFT+CTRL+ESC Launches Task Manager

SHIFT when you insert a CD Prevent the CD from automatically playing

WIN Display or hide the Start menu

WIN+BREAK Display the System Properties dialog box

WIN+D Minimizes all Windows and shows the Desktop

WIN+E Open Windows Explorer

WIN+F Search for a file or folder

WIN+F+CTRL Search for computers

WIN+L Locks the desktop

WIN+M Minimize or restore all windows

WIN+R Open the Run dialog box

WIN+TAB Switch between open items

Windows Explorer Shortcuts

2008-06-02T07:19:00.000-07:00

CTRL+ESC - Display the Start menu

CTRL+A - Select all items

CTRL+X - Cut selected item(s)

CTRL+C - Copy selected item(s)

CTRL+V - Paste item(s)

CTRL+Z - Undo last action

CTRL+(+) - Automatically resize the columns in the right hand pane

SHIFT+F10 - Display the item's context menu

SHIFT+DELETE - Delete an item immediately

ALT+SPACEBAR - Display the current window’s system menu

ALT+RIGHT ARROW - Move forward to a previous view

ALT+LEFT ARROW - Move backward to a previous view

ALT+TAB - Switch to the window you last used

ALT+F4 - Close the current window or quit

ALT+ENTER - View an item’s properties

BACKSPACE - View the folder one level up

TAB - Move forward through options

F2 - Rename selected item

F3 - Display Find application

F5 - Refresh window contents

F6 - Switch between left and right panes

F10 - Activate the menu bar in programs

Internet Explorer Shortcuts

2008-06-02T07:15:00.000-07:00

CTRL+A - Select all items on the current page

CTRL+D - Add the current page to your Favorites

CTRL+E - Open the Search bar

CTRL+F - Find on this page

CTRL+H - Open the History bar

CTRL+I - Open the Favorites bar

CTRL+N - Open a new window

CTRL+O - Go to a new location (Open)

CTRL+P - Print the current page or active frame

CTRL+S - Save the current page

CTRL+W - Close current browser window

CTRL+ENTER - Adds the http://www. (url) .com

CTRL+TAB - Move forward between frames

CTRL+C - Copy selected items to the clipboard

CTRL+V - Insert contents of the clipboard

SHIFT+CLICK - Open link in new window

SHIFT+CTRL+TAB - Move back between frames

SHIFT+F10 - Display a shortcut menu for a link

SHIFT+TAB - Move back through the items on a page

ALT+HOME - Go to your Home page

ALT+RIGHT ARROW - Go to the next page

BACKSPACE - Go to the previous page

HOME - Move to the beginning of a document

TAB - Move forward through items on a page

END - Move to the end of a document

ESC - Stop downloading a page

ENTER - Activate a selected link

HOME - Move to the beginning of a document

END - Move to the end of a document

F1 - Display Internet Explorer Help

F5 - Refresh the current page

F4 - Display list of typed addresses

F6 - Change Address bar and page focus

F11 - Toggle full-screen view

Windows Commands undocumented

2008-05-27T01:12:00.000-07:00

System Configuration Utility (can use to control starup programs)

msconfig

System Configuration Editor

sysedit

Direct X Troubleshooter (Diagnose & test DirectX, video & sound cards)

dxdiag

System Information

msinfo32

Volume Control

sndvol32

Task Manager

taskmgr

Administrative Tools

control admintools

User Accounts

control userpasswords2

control userpasswords

Folders Properties

control folders

Display Properties

control desktop

control color (w/Appearance Tab Preselected)

Mouse Properties

control mouse

Network Connections

control netconnections

Keyboard Properties

control keyboard

Printers and Faxes

control printers

Fonts

control fonts

Scheduled Tasks

control schedtasks

Component Services

dcomcnfg

Internet Information Server

inetmgr

Remote Desktop

mstsc

Performance Monitor

perfmon

Disk Partition Manager

diskpart

ODBC Data Source Administrator

odbcad32

Network shared folder wizard (creates shared folders on network)

shrpubw

Performance Monitor

perfmon.msc

Disk Management

diskmgmt.msc

Computer Management

compmgmt.msc

Event Viewer

eventvwr.msc

Device Manager

devmgmt.msc

Services

services.msc

Windows Management Infrastructure(Windows Management Instrumentation)

wmimgmt.msc

Resultant Set of Policy (XP Prof)

rsop.msc

Group Policy Editor (XP Prof)

gpedit.msc

Local Security Settings

secpol.msc

Local Users and Groups

lusrmgr.msc

Shared Folders

fsmgmt.msc

Indexing Service

ciadv.msc

Removable Storage

ntmsmgr.msc

Removable Storage Operator Requests

ntmsoprq.msc

Certificate Manager

certmgr.msc

Disk Defragment

dfrg.msc

Windows Explorer

explorer.scf

Windows Explorer

explorer

Internet Explorer

iexplore

Private Character Editor (allows creation or modification of characters)

eudcedit

Character Map

charmap

Clipboard Viewer (views contents of Windows clipboard)

clipbrd

Disk Cleanup

cleanmgr

Dr. Watson System Troubleshooting Utility

drwtsn32

SQL Client Configuration

cliconfg

DDE Shares

ddeshare

Iexpress Wizard (Create self-extracting / self-installing package)

iexpress

Object Packager

packager

Program Manager (Legacy Windows 3.x desktop shell)

progman

Remote Access phone book

rasphone

Mcft Synchronization Manager

mobsync

File Signature Verification Tool

sigverif

Driver Verifier Utility

verifier

Logs You Out Of Windows

logoff

Shuts Down Windows

shutdown

Check Disk Utility

chkdsk

Command Prompt

cmd

Registry Editor

regedit

Registry Editor (Don't work on XP Prof)

regedit32

Display Properties

desk.cpl

Internet Properties

inetcpl.cpl

Sounds and Audio

mmsys.cpl

System Properties

sysdm.cpl

User Account Management

nusrmgr.cpl

Mouse Properties

main.cpl

Network Connections

ncpa.cpl

ODBC Data Source Administrator

odbccp32.cpl

Accessibility Controls

access.cpl

Add Hardware Wizard

hdwwiz.cpl

Add/Remove Programs

appwiz.cpl

Phone and Modem Options

telephon.cpl

Power Configuration

powercfg.cpl

Scanners and Cameras

sticpl.cpl

Game Controllers

joy.cpl

Findfast

findfast.cpl

Regional Settings

intl.cpl

Phone and Modem Options

telephon.cpl

Power Configuration

powercfg.cpl

Date and Time Properties

timedate.cpl

Automatic Updates

wuaucpl.cpl

Windows Firewall (Not working on my system)

firewall.cpl

Security Center (Not working on my system)

wscui.cpl

Network Setup Wizard (Not working on my system)

netsetup.cpl

Password Properties (Not working on my system)

password.cpl

Printers Folder

printers

Telnet Client

telnet

Utility Manager

utilman

Windows System Security Tool

syskey

Windows Update Launches

wupdmgr

m*cro$oft Chat

winchat

Windows XP Tour Wizard

tourstart

Windows Magnifier

magnify

On Screen Keyboard

osk

Fonts Folder

fonts

Notepad

notepad

Wordpad

wordpad

Calculator

calc

Windows Media Player 5.1 (Retro version of Media Player, very basic)

mplay32

Bluetooth Transfer Wizard (Not working on my system)

fsquirt

IP Configuration

============

ipconfig /all # IP Configuration (Display Connection Configuration)

ipconfig /displaydns # IP Configuration (Display DNS Cache Contents)

ipconfig /flushdns # IP Configuration (Delete DNS Cache Contents)

ipconfig /release # IP Configuration (Release All Connections)

ipconfig /renew # IP Configuration (Renew All Connections)

ipconfig /registerdns # IP Configuration (Refreshes DHCP & Re-Registers DNS)

ipconfig /showclassid # IP Configuration (Display DHCP Class ID)

ipconfig /setclassid # IP Configuration (Modifies DHCP Class ID)

System File Checker Utility

===================

sfc /scannow # System File Checker Utility (Scan Immediately)

sfc /scanonce # System File Checker Utility (Scan Once At Next Boot)

sfc /scanboot # System File Checker Utility (Scan On Every Boot)

sfc /revert # System File Checker Utility (Return to Default Setting)

sfc /purgecache # System File Checker Utility (Purge File Cache)

sfc /cachesize=x # System File Checker Utility (Set Cache Size to size x)

Windows Games

============

Hearts Card Game

mshearts

Free Cell Card Game

freecell

Minesweeper Game

winmine

Spider Solitare Card Game

spider

If Installed

========

Direct X Control Panel (If Installed)*

directx.cpl

Java Control Panel

javaws

Quicktime

QuickTime.cpl

Opens AC3 Filter

ac3filter.cpl

Nview Desktop Manager

nvtuicpl.cpl

Java Control Panel

jpicpl32.cpl

Microsoft Access

msaccess

Power Point

powerpnt

Microsoft Word

winword

Microsoft Excel

excel

FrontPage

frontpg

Adobe Acrobat Reader 6.0

acrord32

Adobe Illustrator

Illustrator

Adobe Photoshop cs 8.0

photoshop

Adobe ImageReady 8.0

imageready

MacroMedia Flash 8

flash

CloneCD v4.2

clonecd

CloneDVD v2

clonedvd2

Nero Smart

nerostartsmart

Nero Burning Rom

nero

Image Drive

imagedrive

Nero Vision

nerovision

Nero Player (Show Time)

showtime

Nero Media Player

neromediaplayer

JetAudio Player 6

jetaudio

Realplayer

realplay

Visual C++

MSDEV

WinRAR

winrar

Mozilla FireFox Internet Explorer

firefox

AVG AntiVirus 7.0

avgw

Special Commands

=============

Runas

example:

runas /user:localmachinenameadministrator cmd

To start an instance of the command prompt as an administrator on the local computer

MicroSoft Mangement Console (.msc)

msc may means MicroSoft Console

mmc.exe MMCMainFrame

Network connections

control.exe netconnections

Command Base Utility :

REXEC (Remote Execution) , RSH (Remote Shell) and Telnet

Transfer Utilities : FTP , RCP, TFTP

Printer Utilities : LPR, LPQ

Windows Movie Maker

moviemk

Windows Messenger

msmsgs

Microsoft Outlook Express

msimn

NetMetting

conf

Adding Radio Button to GridView

2008-05-20T03:38:00.000-07:00

First add a literal control as shown below and in GridView1_RowCreated event which will run for every row. assign the text value of literal control. and u can add as many attributes u want in radio button.make one thing very clear that u can use web control or html server control because they are server control and when your gridview rendered it generate there own unique id and name. when you want to change the value or their status like checked/unchecked use Literal lc = (Literal)e.Row.FindControl("Literal1"); and change the text of literal control based on your requirement. where e is GridViewRowEventArgs you will get it in any gridview specific event like click etc.

<asp:GridView ID="GridView1" runat="server">

<asp:TemplateField HeaderText="Radio"> <ItemTemplate>

<asp:Literal ID="Literal1" runat="server"></asp:Literal>

</ItemTemplate>

</asp:TemplateField>

</asp:GridView>

protected void GridView1_RowCreated(object sender, GridViewRowEventArgs e)

{

if (e.Row.RowType == DataControlRowType.DataRow)

{

Literal lc = (Literal)e.Row.FindControl("Literal1");

lc.Text = lc.Text = String.Format("<input type='radio'

name='radiogroup' id=" + e.Row.RowIndex);

if (e.Row.RowIndex == 0)

lc.Text = lc.Text + " checked='checked'";

lc.Text = lc.Text + "/>";

}

Detecting async postback start & end

2008-05-19T12:19:00.000-07:00

When you use the UpdatePanel control you probably also want to display some kind of progress bar to the user so they can see when the async. postback starts and when it's done, at least something that indicate that some work are being done and they need to wait until it's done. This can be done by using the UpdateProgress control shipped with ASP.Net Ajax 1.0 Extension. If you use the UpdatePanel control and specify an AsyncPostBackTrigger and also associate the UpdateProgress to an UpdatePanel, the UpdateProgress control will not be displayed.Below is the solution


<%@ Page Language="C#" AutoEventWireup="true" 
    CodeFile="PleaseWait.aspx.cs" 
    Inherits="GridViewasInsert" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 
    Transitional//EN" 
    "http://www.w3.org/TR/xhtml1/DTD/
    xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">

<head runat="server">
  <title>Untitled Page</title>
</head>
<body>
  <form id="form1" runat="server">


      <asp:ScriptManager ID="s" runat="server">

      </asp:ScriptManager>
      <div>
          <asp:Button ID="Button1" runat="server" 
                Text="AA" OnClick="Button1_Click" />


          <asp:UpdatePanel ID="UpdatePanel1" 
                           runat="server">

              <ContentTemplate>
                  gfdgdg
              </ContentTemplate>

              <Triggers>
                  <asp:AsyncPostBackTrigger 
                    ControlID="Button1" 
                    EventName="Click" />
              </Triggers>
          </asp:UpdatePanel>

          <asp:UpdateProgress 
                    AssociatedUpdatePanelID="UpdatePanel1" 
                    ID="UpdateProgress1" runat="server">
              <ProgressTemplate>
                  Please wait, update in progress
              </ProgressTemplate>
          </asp:UpdateProgress>
      </div>
  </form>


  <script language="javascript" type="text/javascript">

 var prm = Sys.WebForms.PageRequestManager.getInstance();
 prm.add_initializeRequest(InitializeRequest);
 prm.add_endRequest(EndRequest);
 var postBackElement;

 function InitializeRequest(sender, args)
 {
    if (prm.get_isInAsyncPostBack())
       args.set_cancel(true);
    postBackElement = args.get_postBackElement();

    if (postBackElement.id == 'Button1')
       $get('UpdateProgress1').style.display = 'block';
 }
 function EndRequest(sender, args)
 {
     if (postBackElement.id == 'Button1')
        $get('UpdateProgress1').style.display = 'none';
 }
  </script>

</body>
</html>

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;

public partial class GridViewasInsert 
        : System.Web.UI.Page
{
   protected void Page_Load(object sender,
                  EventArgs e)
   {
        //Replace This when using on live server
       System.Threading.Thread.Sleep(3000);

   }
   protected void Button1_Click(object sender,
                  EventArgs e)
   {
       Response.Redirect("AnotherPage.aspx");
   }
}

About ToogleBase

2008-05-18T06:37:00.000-07:00

Welcome to Tooglebase.blogger.com

Hope this blog is going to help you all