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Contents Data What is DataBase What is DBMS Types of DBMS Oracle Introduction SQL Introduction SQL Statements

Data In simple words data can be facts related to any object in consideration. For example your name, age, height, weight, etc are some data related to you. A picture , image , file , pdf etc can also be considered data.

Database Database is a systematic collection of data. Databases support storage and  manipulation of data. Databases make data management easy. Let's discuss few examples. An online telephone directory would definitely use database to store data pertaining to people, phone numbers, other contact details, etc. Let's also consider the facebook. It needs to store, manipulate and present data related to members, their friends, member activities, messages, advertisements and lot more.

DBMS Database Management System (DBMS) is a collection of programs which enables its users to access database, manipulate data, reporting / representation of  data . It also helps to control access to the  database.  Integrated Data Store (IDS) is said to be the first DBMS in history.

Types of DBMS There are 4 major types of DBMS Hierarchical Network DBMS Relational DBMS Object Oriented Relation DBMS

Hierarchical DBMS This type of DBMS employs the "parent-child" relationship of storing data. This type of DBMS is rarely used nowadays. Its structure is like a tree with nodes representing records and branches representing fields. Example-The windows registry used in Windows XP is an example of a hierarchical database. Configuration settings are stored as tree structures with nodes.

NETWORK DBMS This type of DBMS supports many-to many relations. This usually results in complex database structures.   Example-RDM Server is an example of a database management system that implements the network model

Relational DBMS This type of DBMS defines database relationships in form of tables, also known as relations. Unlike network DBMS, RDBMS does not support many to many relationships. Relational DBMS usually have pre-defined data types that they can support. This is the most popular DBMS type in the market. Examples of relational database management systems include MySQL, Oracle, and Microsoft SQL Server database.

Object Oriented Relation DBMS This type supports storage of new data types. The data to be stored is in form of objects. The objects to be stored in the database have attributes (i.e. gender, age) and methods that define what to do with the data. Example- PostgreSQL is an example of an object oriented relational DBMS.

ORACLE Introduction Oracle Database (commonly referred to as Oracle RDBMS or simply as Oracle)] produced and marketed by Oracle Corporation. Oracle 11g –g stands for Grid Computing Grid means Distributed Latest Version 12c- c stands for Cloud.

SQL Introduction Structured Query language (SQL) pronounced as "S-Q-L" or sometimes as "See-Quel"is actually the standard language for dealing with Relational Databases. SQL programming can be effectively used to insert, search, update, delete database records. Relational databases like MySQL Database, Oracle, Ms SQL server, Sybase, etc uses SQL

SQL Statements

The five main categories of SQL statements are as follows: 1. DML (Data Manipulation Language) 2. DDL (Data Definition Language) 3. DCL (Data Control Language) 4. TCL (Transaction Control Language) 5. DRL(Data Retrieval Language)

DML(DATA MANIPULATION LANGUGAGE) DML statements affect records in a table. These are basic operations we perform on data such as selecting a few records from a table, inserting new records, deleting unnecessary records, and updating/modifying existing records. DML statements include the following: SELECT – select records from a table INSERT – insert new records UPDATE – update/Modify existing records DELETE – delete existing records

DDL (Data Definition Language) DDL statements are used to alter/modify a database or table structure and schema. These statements handle the design and storage of database objects. CREATE – create a new Table, database, schema ALTER – alter existing table, column description DROP – delete existing objects from database

DCL (Data Control Language) DCL statements control the level of access that users have on database objects. GRANT - gives user's access privileges to database GRANT – allows users to read/write on certain database objects REVOKE - withdraw access privileges given with the GRANT command REVOKE – keeps users from read/write permission on database objects

TCL command Transaction Control Language(TCL) commands are used to manage transactions in database.These are used to manage the changes made by DML statements. It also allows statements to be grouped together into logical transactions. Commit command Commit command is used to permanently save any transaaction into database. Following is Commit command's syntax, commit;

Rollback command This command restores the database to last commited state. It is also use with savepoint command to jump to a savepoint in a transaction. Following is Rollback command's syntax, rollback to savepoint-name;