Computer Engineering

. Normalization Normalization is the process of organization data in a database to reduce the redundancies. The process of normalization includes both creating tables and establishing relationship between those tables using rules designed to protect the data and to make the database more flexible. These goals are achieved by eliminating both redundancies in the data fields as well as the inconsistent dependency between various fields. The data is said to be redundant if same data is found in more than one place in a table. The following figure illustrates the unnormalized and normalized database. Fig: Next stage of normalized table When a person makes a phone call, the caller's information is stored in the table. If the same person makes a phone call next time, LastName, FirstName, Birthday, HomePhone, HomeCity, HomeStreet of the caller is same as previous attempt. Only, DateOfCall and CallDescription may be different. So, the table is broken down into two, Contact table for the re

 . Course Content of Computer Science Grade 12 Unit 1: DBMS Concept 1.1  Introduce Database Management System (DBMS) with its aspects 1.2  State the advantages of using DBMS 1.3  Define Data Definition Language (DDL)  and  Data Manipulation Language (DML) 1.4  Introduce and use database model 1.5  State the concept of normalization 1.6  Compare between centralized and distributed database 1.7  Introduce database security and apply it Unit 2: Concept of Network and Data Communication 2.1  Describe the communication system with its basic elements and model 2.2  Describe the data communication with its elements and mode 2.3  Define and apply LAN and WAN 2.4  Describe transmission medium and use it 2.5  Define terminologies for transmission impairments 2.6  Introduce network architecture 2.7  Define basic terms and tools used in computer network 2.8  Define network tools, devices and topologies and usethem 2.9  State the concept of OSI Reference Model and Internet Protocol Addressing Unit

 . The C programming language was designed by Dennis Ritchie in the early 1970's at Ball Laboratories. It was first used system application language for this unit operating system. Object oriented Programming (OOP) is a computer programming model that organizes software design around data, or objects, rather than functions and logic. An object can be defined as a data field that has unique attributes and behavior. OOP language are not necessarily restricted to the object oriented programming paradigm. Some languages, such as JavaScript, Python and PHP, all allow for both procedural and object oriented programming styles. Programming Language Paradigms  1. Machine Language          Machine Language rest on the concept of electricity being turned "On" or "Off" from this On/Off, Yes/No two statement system binary system is constructed.  2. Assembly Language           Assembly Language used symbol for programming like (AND, SUB, MULT, DIV) statement as used text pro

. Structure Union A structure can store multiple values of the different members. A union stores one value at a time for all of its members. A structure's total size is the sum of the size of every data member. A union's total size is the size of the largest data member. User can access or retrieve any member at a time. User can access or retrieve only one member at a time. You can use a struct keyword to define a structure. You can use a union keyword to define a union. It occupies space for each and every member written in inner parameters. It occupies space for a member having the highest size written in inner parameters. It supports flexible array. It does not support a flexible array.  

 . A query is a more powerful type of filter that can gather information from multiple table in a relational database. For eg. The query can include field names such as "customer" and "city" from a customer table and "order date" from the order table as follows: Some database systems provide social windows or forms for creating queries. Because of similar structure of almost all databases, a common type of query language is developed. In mid 1970's a language called Structured English Query Language (SEQUEL) was developed by mainframe database developers. Later SEQUEL was changed to SQL with some improvement in it. SEQUEL and SQL are the English like query language that allow user to query a database without much knowing about the underlying database. Because SQL is such a powerful tool, most of the PC based DBMS have the SQL query tool but they can have some variation of the SQL with some extra feature added to it. Example of SQL implemented database

 . A Database is a repository for collection of related data or facts. A database contains a collection of related items or facts arranged in a specific structure. The most obvious example of a non computerized database is a telephone directory. Telephone companies now use an electronic database program to produce their printed phone books. Sometimes, we see a specialized phone book that is sorted not only by last name, but by other items such as phone number or street address. These books are easy to produce because the telephone company's electronic database can sort and organize the data in many different ways. Database programs can also sort lists of data, arranging them in alphabetical, numeric, or chronological order and can search or query data with different conditions. Features of Database  The data in a database should have following features Shared : Data in a database is sharing among different user and application. Validity :  Data should be correct with respect. Secur

. PHP stands for Hypertext Pre-Processor that earlies stood for personal homepages.  It is a server-side scripting language that is used to develop static or dynamic website or web application. The client computers excessing the PHP script required web browser only. A PHP file contains PHP tags and ends with the extension. ".php" The Syntax for PHP is given bellow: <? php          echo "Hello World";     ?> Operators and Variables in PHP

 . Operator  An Operator is a symbol that perform certain mathematical and logical operation on operator. It is define as an action upon the two possible values. Operators are used to program operation on the variables and values.  PHP Operators are of following types: Arithmetic Operator Assignment Operator  Logical Operator Comparison Operator Conditional Operator Increment / Decrement Operator Concatenation Operator 1. Arithmetic Operator Arithmetic operator are used to preform arithmetic operation on numeric values. 2. Assignment Operator An assignment operator is mainly responsible for assigning a value to a variable in a program. It is used to value to the variable.  Assignment Same As Description x = y x = y left operand and right operand are same. x + = y X = X + y left operand get added value of right operand. x - = y x = x - y

 .  Server-side Scripting Client-Side Scripting   Server-Side Scripting language is used to create dynamic page based on number of conditions when the user browses makes a request to the server. Client-Side Scripting is used when the uses browse already has all the code and the page is altered on the basis of user input. The Web Server executes the server-side scripting that produces the page to be sent to the browser.    The browser receives the page sent by the server and executes the client-side script.   Server-Side scripting is used to connect to the data base that reside on the web server. Client-Side scripting can not be used to connect to the database on the webserver.    Server-Side scripting can access the file system. It cannot access the file system.   Server-Side scripting can not be blocked by user. Example: PHP, Ruby, Python, Asp etc. Client-Side