Database Management System

Database Management System

SAP Copyrights© 2007 Amplify Department of Information Technology

What is Data? By Data we mean the known fact that can be recorded and that has a meaning.  Meaningful facts, text, graphics, images, sound, video segments that can be recorded and that have implicit meaning. 

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What is Database? 

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DATABASE: An organized body of related information. Database is an organized collection of related information. A database is a collection of information stored in a computer in a systematic way, such that a computer program can consult it to answer questions. SAP Copyrights© 2007 Amplify School of Information Technology

A

database is a collection of data that is organized so that its contents can easily be accessed, managed and updated.  Eg:  College Database, Hospital Database, Enterprise database etc. SAP Copyrights© 2007 Amplify School of Information Technology

College Database Student

Faculty

Subject

Books

Subject_allocation Stream Batch

course Attendance data

Marks

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Hospital Database Patient

Doctors

Equipments

Employees

Duties

Batch

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Enterprise Database

Employees

Customers

Purchase Order

Materials

Vendors

Sales Order

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What is DBMS? 

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The software used to manage and query a database is known as a database management system (DBMS). Database management system is the collection of inter-related data and the way of managing data in the database.

SAP Copyrights© 2007 Amplify School of Information Technology

Applications of DBMS 

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Banking: for customers information, accounts, loans and banking transactions Airlines: for reservations and schedule information Universities: for student information, course registration and grades Credits and transactions: for purchases on credit card and generating monthly bills, maintaining balances Finance Sales Online retailers Manufacturing Human resources SAP Copyrights© 2007 Amplify School of Information Technology

What is RDBMS?  

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It is one of the type of DBMS. In this information is stored in the form of tables. In this tables are related with each other using primary key and foreign key relations. Oracle is example of RDBMS.

SAP Copyrights© 2007 Amplify School of Information Technology

What is SQL?         

SQL SQL SQL SQL SQL SQL SQL SQL SQL

stands for Structured Query Language allows you to access a database is an ANSI standard computer language can execute queries against a database can retrieve data from a database can insert new records in a database can delete records from a database can update records in a database is easy to learn SAP Copyrights© 2007 Amplify School of Information Technology

SQL commands are divided into 4 category

SQL commands DDL

DML

DCL

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TCL

DDL  

Data Definition Language (DDL) statements are used to define the database structure or schema. Some examples are:    

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CREATE - to create objects in the database ALTER - alters the structure of the database DROP - delete objects from the database TRUNCATE - remove all records from a table, including all spaces allocated for the records are removed COMMENT - add comments to the data dictionary RENAME - rename an object

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DML 

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Data Manipulation Language (DML) statements are used for managing data within schema objects. Some examples:    

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SELECT - retrieve data from the a database INSERT - insert data into a table UPDATE - updates existing data within a table DELETE - deletes all records from a table, the space for the records remain MERGE - UPSERT operation (insert or update) SAP Copyrights© 2007 Amplify School of Information Technology

DCL  Data

Control Language (DCL) statements. Some examples:  GRANT - gives user's access privileges to database.  REVOKE - withdraw access privileges given with the GRANT command. SAP Copyrights© 2007 Amplify School of Information Technology

TCL 

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Transaction Control (TCL) statements are used to manage the changes made by DML statements. It allows statements to be grouped together into logical transactions. Some Examples are:  

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COMMIT - save work done SAVEPOINT - identify a point in a transaction to which you can later roll back ROLLBACK - restore database to original since the last COMMIT

SAP Copyrights© 2007 Amplify School of Information Technology