INTRODUCTION OF DBMS

All Basic Definition

YouQ TM

1. What is DBMS? “A Database Management System (DBMS) is

a program that controls creation, maintenance and use of a database. DBMS can be termed as File Manager that manages data in a database rather than saving it in file systems”.

YouQ TM

YouQ TM

DATA ARCHITECTURE

YouQ TM

What is RDBMS?

RDBMS stands for Relational Database Management System.

RDBMS store the data into the collection of tables, which is related by common fields between the columns of the table. It also provides relational operators to manipulate the data stored into the tables.

RDBMS

Oracle

My Sql

Postage

Server

Sql Serve

rr

YouQ TM

3. What is SQL? SQL stands for Structured Query Language ,

and it is used to communicate with the Database. This is a standard language used to perform tasks such as retrieval, updation, insertion and deletion of data from a database.

Standard SQL Commands are Select.

YouQ TM

4. What is a Database? Database is nothing but an organized form of

data for easy access, storing, retrieval and managing of data. This is also known as structured form of data which can be accessed in many ways.

YouQ TM

What are tables and Fields? A table is a set of data that are organized in a

model with Columns and Rows. Columns can be categorized as vertical, and Rows are horizontal.

A table has specified number of column called fields but can have any number of rows which is called record.

YouQ TM

TYPE OF KEY IN DBMS

KEY

PRIMERY KEY

SUPER KEY

CANDIDATE KEY

FOREIGN KEY

ALTERNATE KEY

COMPOUND KEY

YouQ TM

Primary Key Primary key is a set of one or more fields/columns of a table that

uniquely identify a record in database table. It can not accept null, duplicate values. Only one Candidate Key can be Primary Key.

Super Key Super key is a set of one or more than one keys that can be used

to identify a record uniquely in a table.

Candidate Key A Candidate Key is a set of one or more fields/columns that can

identify a record uniquely in a table. There can be multiple Candidate Keys in one table. Each Candidate Key can work as Primary Key.

Foreign Key Foreign Key is a field in database table that is Primary key in

another table. It can accept multiple null, duplicate values. 

YouQ TM

YouQ TM

What is a join? An SQL JOIN clause is used to combine rows from two

or more tables, based on a common field between them.

DIFFERENT TYPE OF JOINS INNER JOIN: Returns all rows when there is at least

one match in BOTH tables LEFT JOIN: Return all rows from the left table, and

the matched rows from the right table RIGHT JOIN: Return all rows from the right table, and

the matched rows from the left table FULL JOIN: Return all rows when there is a match in

ONE of the tables

YouQ TM