29 September, 2013

INTRODUCTION TO JAVA AND JAVA EDITIONS AND NUMBER SYSTEMS IN JAVA

java

HISTORY OF JAVA AND DOWNLOAD(PDF)

what is java:
java is a object oriented,platform independent programming language from sun micro system which is released into the marked on the name of development of the distributed applications.
what is java slogan:
"Write Once Run Anywhere "(WORA)
java is a platform independent programming language.it means that program is written once and the program is executed irrespective of the operating system.
why java is suitable for internet:
security problems on internet are eliminated through java.java is a system independent,java is executable on any platform
JAVA HISTORY:
IN 1990,sun microsystems inc., USA is developed software for remotes..in 1993,oak language is developed,by that time some company is registered oak name,for this reason they named as "java".
in 1995,sun world conference has given entire details of java.

javajavajava software all copy rights are purchased oracle

CLICK HERE DOWNLOAD PDF DOCUMENT

java editions:

Sun micro systems provides ,with the advent of java,new versions had multiple configurations built for different types of platforms.those are

JSE
JEE
JME.

JSE:java platform,standard edition:
JSE stands for java platform,standard edition,it is specification used to develop fundamental
java application they may be standard or network.

JEE:java platform,enterprise edition:

JEE stands for java platform, enterprise edition,it is specification used to develop business
solutions for network (or)JEE is specification that provides an environment to run the web components and the enterprise components.

JME:java platform,micro edition:
JEE stands for java platform, micro edition,it is specification used for developing wireless and
embedded system.embedded system is software,which directly installed into hardware.
java software:
   java software is cotegorized in to two types
JAVA=JDK+JRE
  JDK
   it stands for java development kit
JRE:
it stands for java runtime environment
          JRE=JVM+JAVA LIBRARY

if java programs have to run we required the jvm and java library.jvm will starts execution of java
program from main method only.

in java every statement must end with semi colon(;).
java is case sensitive programming language.

In this real world we have 4 types of number systems they are:
1.binary number system     [format:0,1]
2.octal number system             [format:0,1----7]
3.decimal number system        [format:0,1-----9]
4.hexa decimal system           [format:0,1---9,a,b,c,d,e,f ]
genarally we use the decimal number system in any programming language.

In java we can represent the binary values by giving ob infront of the number
ex: int ob10;(correct)
   int x=o4235;(wrong)

representation of the binary number feature is introduced in java 1.7

we can represent the octal values in java programming language by giving o infront of the number
ex: int i=o24;(correct)
        int k=o248;(wrong)[because octal range 0-7]

we can represent the hexa decimal values in java programming language by giving ox infront of the number
ex: int i=ox123;(correct)
        int k=ox245a;(wrong)
         int k=123a;(wrong)

note:JVM takes the binary data ,octal data,decimal data,hexa decimal data convert in the form of decimal format and give the output as adecimal
example programme:
class ndemo
{
public static void main(String args[])
{
int i=24;
int j=o72;
int k=ox2a;
int l=ob10;
System.out.println(i);
System.out.println(j);
System.out.println(k);
System.out.println(l);
}
}
note:this programme run java 1.7 or above versions because binary values format does not suppport java 1.7 below versions.
output:
24
58
42
2

HOW TO PATH SET IN JAVA SOFTWARE

After install the java software following this steps:
step 1:
select "my computer" icon and right click mouse button.
now click on "properties" option.it provides a window.click "advanced" tab and click
"environmental variables" window.

now select the path in system variables and click"edit" button.the "edit system variables" window will open.
add "c:\program files\java\jdk1.7.0_05\bin" to 'variable value' and click 'ok','ok' and 'ok' buttons.

now set the class path variable and set its values to "c:\program files\java\jdk 1.7.0-05\lib\tools.jar"
and "c:\program files\java\jdk 1.7.0-05\jre\lib\rt.jar". if this variable has not been declared eariler then create a new system variable by clicking on "new" button and give variable name as "classpath" and variable value
as "c:\program files\java\jdk 1.7.0-05\lib\tools.jar;c:\program files\java\jdk 1.7.0-05\jre\lib\rt.jar;.;"
now click "ok".this variable is used to complie java programs

AND restart your computer

INTRODUCTION TO ORCLE AND SUB LANGUAGES COMMANDS

oracle

INTRODUCTION TO ORACLE

ORACLE is a powerful rdbms product that provides efficient and effective solutions for major database.An oracle data base system can easily take advantage of distributed processing by using its client/server architecture.
                  ORACLE IS A COMBINATION OF SQL AND PL/SQL.
FIRST KNOWN SQL:
WHAT IS SQL:
           SQL stands for structured query language.SQL is used to communicate with a database.According to ANSI(american national standards institute),it is the standard language for relational database management syatems.SQL statements are used to perform tasks such as update data on a database.or retrieve data from database.some common relational database management systems that use SQL are:oracle,sybase,microsoft sql server,access,ingres,etc.
                                               it is non procedural language which is used to communicate with any type of database.this language was developed by german scientist mr E.F CODD AT 1968 in 1970 ANSI approved this language and 1972 sql was released in the market.
FEATURES OF SQL:

it is a non-procedural language
it can also pronounced as SEQUEL
it is not a case sensitive language.
it can be called as natural language interface because almost all sql commands similar to normal english language
it is the common language to interact with any type of database such as oracle,db2 etc.

SUB LANGUAGES OF SQL:
it was divided into following types.

data defination language(DDL)
data manipulation language(DML)
data retrieval language(DRL)
transaction control language(TCL)
data control language(DCL)

PROPERTIES OF RDBMS:

1.data should store in the form of a table.a table can be different as collection of rows&columns
A horizontal lines as Rows or Records/touples
A vertical lines are known as fields or attributes/columns
the intersection of rows&columns is known as cell
a cell is a place where we can store or a data.the other name of table can be known as entity/object.
table/entity/object:
fields/attributes/columns

rows/records/touples

2.table should not contain duplicate column3.while do inserts the records the table user no need to follow any specific order.
4.data base should not contain duplicate objects
5.while do defines columns in the table user follow no need to order

E-R DIAGRAMS:

this concept was developed by a u.s scientist MR PETER CHAN ,this is the diagramatical representation of manual database when we design E-R diagrams we need to use following symblos.

→ Connection

ex:draw E-R diagram which represent the relation between sales representive and customer

SUB LANGUAGE COMMANDS:

1.DATA DEFINATION LANGUAGE COMMANDS:

WHAT IS DATA DEFINITION LANGUAGE?
this is first sub language in sql which is used to define database objects such as table,view,stored procedure,function and trigger etc.a data definition language has a pre-defined syntax for describing data
this language contains 5 commands those are

CREATE
ALTER
RENAME
TRUNCATE
DROP

CREATE:
           this command is used to create databse objects such as table,view,synonym,trigger,stored procedure etc.,
syntax:
      CREATE TABLE table-name(column 1 data-type-for-column1,
                                           column 2 data-type-for-column2,
............);
ex:
CREATE TABLE user(name char(50),villagename char(50),mobilenum number(10));
RULES FOR CREATING A TABLE:

table name should start with an alphabet and it contains minimum 1 character and maximum 30 characters and it should not allow any space or any special chartcters except _,#,$ and 0 to 9 numbers
a table can have minimum 1 column and maximum 1000 columns
a table can have minimum 0 records and maximum n number of records upto harddisk capacity
oracle keywords should not be used as column names or table names
column name should start with an alphabet and it contains minimum 1 character and maximum 30 characters and it should not allow any space or any special chartcters except _,#,$ and 0 to 9 numbers

ALTER:
this command is used to modify the structure of the table.
using this command we can perform 4 different operations on the table

alter-modify
alter-add
alter-rename
alter-drop

alter-modify:
         this command is used to increse or decrese the size of the column or we can change the data type of the column.
RENAME:
   This command is used to change the table name.
syntax:
          rename old-table-name to new-table-name;
ex:
rename user to cust;
TRUNCATE:
This command is used to delete the records from the existing table permanently.
syntax:
          truncate table
;

ex:
          truncate table user;
DROP:
   This command is used to drop the table from the data base.
syntax:
       drop table
;

ex:
       drop table user;
using drop command once we drop the table those tables are not dropped permantely from the database.
                       thosetables are gone to recycle bin.if you want to get back the table from the recycle bin then we have to use followin command.
FLASHBACK COMMAND:
           This command was introduced from oracle log onwords and which is used to retrieve back the table from the recycle bin
syntax:
          FLASHBACK table
to before drop;

ex:
flashback table user to before drop;
permantely delete from the database :
following this two commands
drop table
purge;

purge table
;

27 September, 2013

GATE SYLLABUS FOR CSE BRANCH

Syllabus for Computer Science and Information Technology (CS)
ENGINEERING MATHEMATICS
Mathematical Logic: Propositional Logic; First Order Logic.
Probability: Conditional Probability; Mean, Median, Mode and Standard Deviation; Random Variables; Distributions; uniform, normal, exponential, Poisson, Binomial.
Set Theory & Algebra: Sets; Relations; Functions; Groups; Partial Orders; Lattice; Boolean Algebra.
Combinatory: Permutations; Combinations; Counting; Summation; generating functions; recurrence relations; asymptotics.
Graph Theory: Connectivity; spanning trees; Cut vertices & edges; covering; matching; independent sets; Colouring; Planarity; Isomorphism.
Linear Algebra: Algebra of matrices, determinants, systems of linear equations, Eigen values and Eigen vectors.
Numerical Methods: LU decomposition for systems of linear equations; numerical solutions of non-linear algebraic equations by Secant, Bisection and Newton-Raphson Methods; Numerical integration by trapezoidal and Simpson’s rules.
Calculus: Limit, Continuity & differentiability, Mean value Theorems, Theorems of integral calculus, evaluation of definite & improper integrals, Partial derivatives, Total derivatives, maxima & minima.
COMPUTER SCIENCE AND INFORMATION TECHNOLOGY
Digital Logic: Logic functions, Minimization, Design and synthesis of combinational and sequential circuits; Number representation and computer arithmetic (fixed and floating point).
Computer Organization and Architecture: Machine instructions and addressing modes, ALU and data-path, CPU control design, Memory interface, I/O interface (Interrupt and DMA mode), Instruction pipelining, Cache and main memory, Secondary storage.
Programming and Data Structures: Programming in C; Functions, Recursion, Parameter passing, Scope, Binding; Abstract data types, Arrays, Stacks, Queues, Linked Lists, Trees, Binary search trees, Binary heaps.
Algorithms: Analysis, Asymptotic notation, Notions of space and time complexity, Worst and average case analysis; Design: Greedy approach, Dynamic programming, Divide-and-conquer; Tree and graph traversals, Connected components, Spanning trees, Shortest paths; Hashing, Sorting, Searching. Asymptotic analysis (best, worst, average cases) of time and space, upper and lower bounds, Basic concepts of complexity classes – P, NP, NP-hard, NP-complete.
Theory of Computation: Regular languages and finite automata, Context free languages and Push-down automata, Recursively enumerable sets and Turing machines, Undecidability.
Compiler Design: Lexical analysis, Parsing, Syntax directed translation, Runtime environments, Intermediate and target code generation, Basics of code optimization.
Operating System: Processes, Threads, Inter-process communication, Concurrency, Synchronization, Deadlock, CPU scheduling, Memory management and virtual memory, File systems, I/O systems, Protection and security.
Databases: ER-model, Relational model (relational algebra, tuple calculus), Database design (integrity constraints, normal forms), Query languages (SQL), File structures (sequential files, indexing, B and B+ trees), Transactions and concurrency control.
Information Systems and Software Engineering: information gathering, requirement and feasibility analysis, data flow diagrams, process specifications, input/output design, process life cycle, planning and managing the project, design, coding, testing, implementation, maintenance.
Computer Networks: ISO/OSI stack, LAN technologies (Ethernet, Token ring), Flow and error control techniques, Routing algorithms, Congestion control, TCP/UDP and sockets, IP(v4), Application layer protocols (icmp, dns, smtp, pop, ftp, http); Basic concepts of hubs, switches, gateways, and routers. Network security – basic concepts of public key and private key cryptography, digital signature, firewalls.
Web technologies: HTML, XML, basic concepts of client-server computing.

12 September, 2013

WHAT IS SQL

it is a non-procedural language
it can also pronounced as SEQUEL
it is not a case sensitive language.
it can be called as natural language interface because almost all sql commands similar to normal english language
it is the common language to interact with any type of database such as oracle,db2 etc.