SQL INTERVIEW QUESTIONS & Answers by Jeevan Raj
1. What is Database [DB]
Ans:- Database is a container where data can be collected systematically Managing and
Manipulation of those data are easy.
Ex:- An online telephone directory uses a database to store their data,
Like :- Name, Address, Phone Number and other contact details
Ex:- An Online Library who has millions of books in order to maintain their data they use
database.
2. What is a Database Management System [DBMS]
Ans:- Database Management System is basically a software, where you can store,
retrieve, define and manage your data in a database.
- Note:- What does data retrieval means?
◼ In Databases, Data Retrieval is the process of identifying and extracting data
from a database based on a query provided by the user or applicant.
3. Types of Database Management System
There are Mainly 4 types of Database Management System
1. Hierarchical Database
2. Network Database
3. Relational Database
4. Object-oriented Database
4. What is Hierarchical Database
1. Hierarchical Database :- (ex:- XML data storage has root node enclosing one or
more child node)
◼ In a hierarchical database data is structured in a tree-like manner.
Those data are stored in hierarchically (Top-down) order and
Also they are represented by Parent child relationship
◼ In hierarchical database Parent can have many children, but in the case of
children, have only one parent
,SQL INTERVIEW QUESTIONS & Answers by Jeevan Raj
5. What is Network Database
1. Network Database:- (ex:- Integrated data store)
◼ The concept of network database model allows all the child to have multiple
parents and also it helps to solve the more complex model
It uses many to many relationship
6. What is Relational Database
1. Relational Database:-
◼ Relational Database are Mostly used DBMS, because of its flexibility and easy
to implement nature.
◼ The model is worked on Normalizing data in the database
◼ Relational model stores the data in fixed structure and manipulated them using
SQL
- Note:- Normalizing data:- Normalizing is the process of organizing the data in
order to reduce data redundancy and improve data integrity.
7. What is Object Oriented Database
1. Object Oriented Database:-
In Object Oriented Database data are stored in the form of objects.
It Maintains a structure which is known as class and display the data within that.
8. Property of RDBMS
Some of the Properties of RDBMS are :-
1. Values are Atomic in RDBMS (Multiple operations can be grouped into a single
entity)
2. Each column can have common name
3. Integrity constraints helps to maintain the data consistency for multiple tables
4. Each row is Different
5. Columns are Different
, SQL INTERVIEW QUESTIONS & Answers by Jeevan Raj
9. Difference between DBMS and RDBMS
DBMS RDBMS
1. Data stored in the form of file 1. Data stored in Table format
format
2. Multiple Data Element are accessible
2. Individual Access of Data together
Element
3. No connection between data 3. Data is stored in the form of table are
4. Data stored in small quantity linked together
5. DBMS Supports a single user 4. Data stored in large amount
6. There is low security while
5. RDBMS Supports multiple users
handling data
7. DBMS does not offer any support 6. It features multiple layers security
for Normalization while handling data [ACID]
7. RDBMS do support multiple
normalization operation.
10. Difference between SQL and MySQL
Parameter SQL MySQL
SQL is a structured query MySQL is an RDBMS to
Definition language, It is useful to store, retrieve, modify and
manage relational Database administrate a database using
SQL
It is readily available through
Complexity You need to learn the SQL
download and installation
language to use it effectively
MySQL is database software,
SQL is a Query Language
Type It uses SQL Language to
query the database
To Query and Operate Allows data handling, storing,
Purpose
database system modifying, deleting in a
tabular format.
1. What is Database [DB]
Ans:- Database is a container where data can be collected systematically Managing and
Manipulation of those data are easy.
Ex:- An online telephone directory uses a database to store their data,
Like :- Name, Address, Phone Number and other contact details
Ex:- An Online Library who has millions of books in order to maintain their data they use
database.
2. What is a Database Management System [DBMS]
Ans:- Database Management System is basically a software, where you can store,
retrieve, define and manage your data in a database.
- Note:- What does data retrieval means?
◼ In Databases, Data Retrieval is the process of identifying and extracting data
from a database based on a query provided by the user or applicant.
3. Types of Database Management System
There are Mainly 4 types of Database Management System
1. Hierarchical Database
2. Network Database
3. Relational Database
4. Object-oriented Database
4. What is Hierarchical Database
1. Hierarchical Database :- (ex:- XML data storage has root node enclosing one or
more child node)
◼ In a hierarchical database data is structured in a tree-like manner.
Those data are stored in hierarchically (Top-down) order and
Also they are represented by Parent child relationship
◼ In hierarchical database Parent can have many children, but in the case of
children, have only one parent
,SQL INTERVIEW QUESTIONS & Answers by Jeevan Raj
5. What is Network Database
1. Network Database:- (ex:- Integrated data store)
◼ The concept of network database model allows all the child to have multiple
parents and also it helps to solve the more complex model
It uses many to many relationship
6. What is Relational Database
1. Relational Database:-
◼ Relational Database are Mostly used DBMS, because of its flexibility and easy
to implement nature.
◼ The model is worked on Normalizing data in the database
◼ Relational model stores the data in fixed structure and manipulated them using
SQL
- Note:- Normalizing data:- Normalizing is the process of organizing the data in
order to reduce data redundancy and improve data integrity.
7. What is Object Oriented Database
1. Object Oriented Database:-
In Object Oriented Database data are stored in the form of objects.
It Maintains a structure which is known as class and display the data within that.
8. Property of RDBMS
Some of the Properties of RDBMS are :-
1. Values are Atomic in RDBMS (Multiple operations can be grouped into a single
entity)
2. Each column can have common name
3. Integrity constraints helps to maintain the data consistency for multiple tables
4. Each row is Different
5. Columns are Different
, SQL INTERVIEW QUESTIONS & Answers by Jeevan Raj
9. Difference between DBMS and RDBMS
DBMS RDBMS
1. Data stored in the form of file 1. Data stored in Table format
format
2. Multiple Data Element are accessible
2. Individual Access of Data together
Element
3. No connection between data 3. Data is stored in the form of table are
4. Data stored in small quantity linked together
5. DBMS Supports a single user 4. Data stored in large amount
6. There is low security while
5. RDBMS Supports multiple users
handling data
7. DBMS does not offer any support 6. It features multiple layers security
for Normalization while handling data [ACID]
7. RDBMS do support multiple
normalization operation.
10. Difference between SQL and MySQL
Parameter SQL MySQL
SQL is a structured query MySQL is an RDBMS to
Definition language, It is useful to store, retrieve, modify and
manage relational Database administrate a database using
SQL
It is readily available through
Complexity You need to learn the SQL
download and installation
language to use it effectively
MySQL is database software,
SQL is a Query Language
Type It uses SQL Language to
query the database
To Query and Operate Allows data handling, storing,
Purpose
database system modifying, deleting in a
tabular format.
