Selasa, 26 Juni 2012

Binary Numbers

Understanding Binary Numbers
Here I will explain about the Definition of Binary Numbers. Binary or binary or binary digits (can be abbreviated to an advanced bit) is one type of the existing number system. Binary numbers consist of digits 0 and 1.


Binary numbers are commonly used in the computing world. Computers use Binary order to communicate between components (hardware) as well as among fellow computer. Because the computer only uses machine language, ie when the computer gets the electrical signal or voltage (Volt), mean value 1. If the computer does not have electricity or voltage signal, means the value 0.


Binary numbers can be converted to other types of number systems like decimal and octal numbers. Humans often use decimal numbers in their everyday lives. Binary Numbers and types of other number systems up to each other mutually. For example, the binary number 00000010 is the number 2 in the Decimal number. Vice versa, if the decimal number 2, the mean number 00.00001 million in Binary.


Binary is also used to construct a data or files contained on the computer. For example, there is a file size of 1MB (Mega Byte). When 1 Byte = 8 bits, then the file is made ​​up of hundreds of bits into a file.


Binary numbers are also used to communicate between the members of computers in a network. Because computers only understand Binary, then the computer menstransmisikan electrical signals to the network device to communicate with each other. Binary numbers are very important in setting up a computer network. To arrange an IP Address, Binary is required.

Rabu, 13 Juni 2012

DCL - DATA CONTROL LANGUAGE


INTRODUCTION to DCL
  • DATA CONTROL LANGUAGE is known as DCL.
  • DCL Statement is used for securing the database.
  • DCL Statement control access to database.
  • As data is important part of whole database system we must take proper steps to check that no invalid user access the data and invalidate the information created by us. To kept such a kind of watch we must have to execute certain DCL statement.
  • Two main DCL statement are Grant and Revoke.
GRANT Statement- Grant privilege(Rights which are to be allocated) is used when we want our database to share with other users, with certain type of right granted to him. Consider that if we want our enduser to have only access privilege to our database, we can grant it by executing command.
- Grant privilege is assigned not only on table object, but also views, synonyms, indexes, sequences,etc.

Syntax:
GRANT PRIVILEGES ON
TO

Example
1)SQL> grant select on
emp to endusers;
- here emp is the table_name whose access right is being allocated to the user who logged on as endusers.
11)SQL>grant insert,select,delete on
emp to operators;
- here user who logged on as operators are granted access, insertion and deletion right on the database.
111)SQL>grant insert (empno, ename, job) on
emp to endusers;
- In some case, we require to hide the information to particular users, this can be achived by grant as in the above command we want to hide the detail of employee salary to endusers, so by executing above command we can hide the information regarding empsalary to the endusers.


REVOKE Statement- Revoke privilege(Rights which are to be de-allocated) is used when we want our database to stop sharing the information with other users, with certain type of right revoked to him. Consider that if we want our operators to have only access privilege to our database, we can revoke it by executing command.
- Revoke privilege is assigned not only on table object, but also views, synonyms, indexes, sequences,etc.

Syntax
REVOKE PRIVILEGES ON
FROM

example
1)SQL> revoke insert, delete on
emp from operators;

DML - Data Manipulation Language

DML itself is a collection of SQL statements that relate to the work process the data in the table - and not associated with changes in the structure and data type definitions of database objects such as table, column, and so forth.
Examples of DML: Taking All the Row Data from table MS_KARYAWAN

SELECT *
FROM ms_karyawan


DML Example: Inserting data into tables ms_karyawan

INSERT INTO ms_karyawan (
                 kode_cabang,
                 kode_karyawan,
                 first_name,
                 last_name,
                 jenis_kelamin)
VALUES ('cab-001', 'kar-001', 'Perizzites', 'Thia', 'Male');

 
Some DML Commands list MySQL 5.0

     CALL
     DELETE
     DO
     HANDLER
     INSERT
     LOAD DATA INFILE
     REPLACE
     SELECT
     TRUNCATE
     UPDATE

DDL - Data Definition Language

As the definition described above, DDL is a set of SQL commands that are used to make (create), modify (alter) and delete (drop) the structure and data type definitions of database objects.

Objects in the database in question - in MySQL - is as follows:

     Database
     Table
     View
     Index
     Procedure (Stored Procedure)
     function
     Trigger

List of DDL commands in MySQL 5.0
Here are examples of DDL commands used in MySQL. Click on the link to see details of the use of the command.

     Preparation of (CREATE)
         CREATE DATABASE
         CREATE FUNCTION
         CREATE INDEX
         CREATE PROCEDURE
         CREATE TABLE
         CREATE TRIGGER
         CREATE VIEW

     Changes (ALTER and RENAME)
         ALTER DATABASE
         ALTER FUNCTION
         ALTER PROCEDURE
         ALTER TABLE
         ALTER VIEW
         RENAME TABLE

     Deletion (DROP)
         DROP DATABASE
         DROP FUNCTION
         DROP INDEX
         DROP PROCEDURE
         DROP TABLE
         DROP TRIGGER
         DROP VIEW

Jumat, 08 Juni 2012

Database


Definition of Database

    
Database is a collection of information stored on the computer in a systematic way to obtain information from the database.
    
The database is a representation of a collection of interrelated facts are stored together, to meet various needs.
    
Database is a collection of related information on a particular subject for a specific purpose as well.
    
Database is a comprehensive array of operational data records of an organization or company, organized and stored in an integrated way by using a method that is able to meet the information needs olehpara optimal user.
Origin of term Database
The term "database" originated from computer science. Although that is more extensive then, put things outside the field of electronics, article about computer databases. Note that similar to the actual database already existed before the industrial revolution in the form of ledgers, receipts hand and a collection of data relating to the business.
Basic Concepts of Database
The basic concept of a database is a collection of records, or pieces of knowledge. A database has structured explanation of the types of facts stored in it: this is called schema explanation. There are many ways to organize the scheme, or modeling the database structure: this is known as a database model or data model. Models commonly used today is the relational model, which, according to a term that is representative of all the information in the form of tables which are interconnected with each table consists of rows and columns (the true definition uses mathematical terminology). In this model, relationships between tables are represented by using the same values ​​between tables.
Tool To Create Database.
Databases can be created and processed using a computer program, which is commonly called the software (the software). Software used to manage and call the query (query) database called the Database Management System (DBMS) or if translated into Indonesian means "System Database Management ".
DBMS consists of two components, namely Relational Database Management System (RDBMS) and Overview of Database Management System (ODBMS). Includes RDBMS Interface Drivers, SQL Engine, Transaction Engine, Relational Engine, and Storage Engine. While ODBMS includes Language Drivers, Query Engine, Transaction Engine, and Storage Engine.
While the level of the software itself, there are two levels of software that allows to create a database include:

    
High Level and Low Level Software Software.
Included in the High Level Software, including Microsoft SQL Server, Oracle, Sybase, Interbase, xBase, Firebird, MySQL, PostgreSQL, Microsoft Access, dBase III, Paradox, FoxPro, Visual FoxPro, Arago, Force, Recital, dbFast, dbXL , Quicksilver, Clipper, Flagship, Harbour, Visual dBase, and Lotus Smart Suite Approach. While that is included in the Low Level Software lainBtrieve and Tsunami Record Manager.
Type of Database
There are 12 types of databases, among others, Operational database, Analyticaldatabase, Data warehousing, Distributed databases, End-user database, external data base, Hypermedia databases on the web, Navigational database, In-memory Data bases, Document-oriented databases, Real-time databases, and RelationalDatabase.

Rabu, 30 Mei 2012

t=v1+v2

DOS stands for Disk Operating System. Refer to the DOS operating system usedon many computers that provide the abstraction and management of secondary storage devices and information. For example, use the file system manages files that exist on the storage device. DOS usually run from one or two discs. This is because the DOS used in the storage media is still very limited ability (most likelyonly 1.4 Megabytes).
There are many types of DOS such as Apple DOS, Commodore DOS, Atari DOSand others. This species is highly dependent on the type of computer device. The most famous type of DOS is the kind that runs on DOS machines are compatiblewith the IBM Personal Computer.

BIOS

BIOS stands for Basic Input / Output System. BIOS is a program code of the first run when the computer starts up (booting). The main function of BIOS is to identify andrecognize the computer hardware. Usually the BIOS is stored in ROM {Read Only Memory) that exist on the motherboard of a computer.
When the computer starts, the BIOS will attempt to identify computer parts below:
 clock generator.
 processors and caches.
 chipset (memory controller and I / O controller).
 system memory.
 All PCI devices
 primary graphics controller.
 Mass storage controllers SATA and IDE controllers fseperti).
 Various I / O controllers (Such a keyboard / mouse and USB).
Once identified, the BIOS will call the program to boot an operating system bootloader {).

Digital circuit

In the above section we have learned about the forms of logic gates based on the truth table. A digital circuit is actually composed of one or more of these logic gates. Consider the example in Figure 3.7. below. If we look at the picture, look atthe top there are four NAND logic gerban notation, one pin for 5 V and the resources of the pin to ground. While on the bottom is a representation of digitalcircuits, namely a 7400 chip.