CBSE 10th | IT 402 Main Book | UNIT-3: RDBMS) | Final Revision Notes
SESSION 1: APPRECIATE CONCEPT OF DATABASE
MANAGEMENT SYSTEM
Database:
1)
A database is an organized
collection of data.
2)
A database is an integrated
collection of data records, files, and other objects.
3)
You
can visualize database as a container of
information.
4)
The
data is typically organized to model
relevant aspects of reality (for example, the availability of rooms in hotels),
in a way that supports processes requiring this information (for example,
finding a hotel with facilities such as Laundry, GYM etc…).
5)
database programs such as Microsoft Access, OpenOffice.org Base, and MySQL,
to organize the data as per your business need.
6)
The
database concept has evolved since the 1960s to ease
increasing difficulties in designing, building, and maintaining complex
information systems (typically with many concurrent end-users, and with a large
amount of diverse data).
7)
Database Management System (DBMS).
8)
A DBMS
is a software package with computer programs that controls the creation,
maintenance, and use of a database.
9)
DBMS
allows organizations to conveniently develop databases for various
applications.
10) A DBMS allows different
user application programs to concurrently access the same database.
11) Well known DBMSs include
Oracle, IBM DB2, Microsoft SQL Server, Microsoft Access, PostgreSQL,
MySQL, FoxPro, and SQLite.
12) Data can be organized into two types:
a.
• Flat File:
Data is stored in a single table. Usually suitable for less
amount of data.
b.
• Relational:
Data is stored in multiple tables and the tables are
linked using a common field. Relational is suitable for medium to large
amount of data.
13) Database Servers are dedicated computers
that hold the actual databases and run only the
DBMS and related software.
14) Typically, databases available
on the database servers are accessed through command
line or graphic user interface tools referred
to as Frontends;
15) Database servers are referred to as Back-ends.
16) Database servers: Such type of data access is referred to as a
client-server model.
17) Advantages of Database · Reduces Data Redundancy, · Sharing of Data, · Data Integrity, · Data Security, · Privacy, · Backup and Recovery, · Data Consistency
18) Data redundancy:
a.
Multiple copies of the same file which lead to data
redundancy. ***(VIMP)***
b.
Reduces
Data Redundancy: there is no
chance of encountering duplicate data.
19) Data integrity
a. Data integrity means that the data is accurate
and consistent in the database.
b.
Data
integrity is very important as there are
multiple databases in a DBMS. All of these databases contain data that is
visible to multiple users.
c.
Data
integrity ensure that the data is
correct and consistent in all the databases & for all the
users.
20) Data Security
a.
Data
Security is an important concept in a
database.
b.
Only authorised
users should be allowed to access the database
and their identity should be authenticated using a username and
password.
c.
Unauthorised
users should not be allowed to access the
database under any circumstances as it violates the integrity
constraints.
21) Privacy
a.
The privacy
rule in a database states that only the authorized users can access
a database according to its privacy constraints.
b.
To secure
data levels are set in the database and a user can only view the
data which is allowed to be seen.
22) Backup and recovery
a.
Database
Management System automatically
takes care of backup and recovery.
b.
The users don't
need to backup data periodically because this is taken
care of by the DBMS.
c.
DBMS restores the database after a crash or system failure
to its previous condition.
23) Data consistency:
24) Data consistency is
ensured in a database because there is no data redundancy.
25) Data Consistency
means there should be multiple mismatching copies of the same data.
26) Data Consistency:
All data appears consistently across the database and must
be same for all the users viewing the database.
27) Data Consistency:
any changes made to the database are immediately
reflected to all the users and there is no data
inconsistency.
28)
Database elements are
used for storing and managing information.
1. Item :- Item is about which
information is stored in the database.
2. Field:- Each question that we
ask about our item is a Field.
3. Record:- Record is a set of
information (made up of fields) stored in your database about one of the items.
4. Value:- Value is the actual
text or numerical amount or date that you put in while adding information
to your database.
29) You may have people’s name, address,
phone number and maybe even their birthdays.
There is a common element here – people.
In this example, each person is considered an “ITEM”.
30) new friends and want to add their information
to your address book. You will ask questions, get
the answers and create a new “record”.
31) When you put all the information together in
a grid (like you do in a spreadsheet), a collection of
similar records creates a table. For example,
(1) Database :- Employee
|
Emp_Code |
Emp_Name |
Emp_Address |
Emp_Designation |
Emp_ContactNo |
Emp_Salary |
|
E001 |
ABC |
Meerut |
Manager |
9876543210 |
Rs.
50,000 |
(2) Item : Employee
(3) Field : Emp_Code , Emp_Name , Emp_Address , Emp_Designation ,
Emp_ContactNo , Emp_Salary
(4) Value : E001 , ABC , Meerut , Manager , 9876543210 , Rs. 50,000
|
E001 |
ABC |
Meerut |
Manager |
9876543210 |
Rs.
50,000 |
(5) Record :
(39)There
are some key features of a database:
(1)
A database can have one
or many tables.
(2)
Each table in a database contains information about one
type of item.
(3)
A database is a container
that holds tables and other objects (Table, Query, Form & Report)
and manages how they can be used.
(4)
When creating a database an important feature
is record uniqueness in every table.
(5)
It is important to be able to distinguish
between different items having duplicate values.
(6)
Uniqueness helps to avoid accidental
duplication of records caused by user or computer error.
(7)
Every table has a key field
which ensures that there are 100% unique values
throughout the database.
(8)
Every database table should have one
or more fields designated as key.
(9)
You can assign a unique value
to this key for differentiating records
that may have similar names or addresses.
RDBMS (Relational
Database Management System):
(40) When data is to be stored, maintained, and
retrieved from multiple tables then special database software
are required known as Relational Database Management System.
(41) The relational model was introduced
by E. F. Codd.
(42) In the RDBMS
data can be integrated using keys. These are Primary
Key, Composite Primary Key, Foreign
Key.
(43) This unique
field is called the Primary Key (PK).
(44) A primary key
is a unique value that identifies a row in a
table.
(45)In our example, ClientID
is the primary key in the Client table.
(46)Primary Keys are also indexed in the database,
making it faster for the database to search for a record.
(47)When primary key
constraint is applied on one or more columns
then it is known as Composite Primary Key.
(48) The referred field
ClientID which occurs in the Sales table is called the Foreign key
(FK).
(49) The foreign key
identifies a column or set of columns in one (referencing) table that refers to
a column or set of columns in another (referenced) table.
(50)The “one” side of a relation
is always the parent, and provides the PK
attributes to be copied. The “many” side of a relation
is always the child, into which the FK attributes
are copied.
(51)Memorize it: one, parent, PK; many,
child, FK
(52)A relational database is
a type of database.
(53)relational database uses a structure that allows us to identify
and access data in relation to another piece of data in the database.
(54) Data in a relational database is organized into tables.
SESSION2:CREATE AND EDIT TABLES USING WIZARD &
SQL COMMANDS
(55) Data in a relational database management system (RDBMS) is organized in
the form of tables.
(56) A relational
database is a collective set of multiple data sets organized
by tables, records and columns.
(57) Relational
database establish a well-defined
relationship between database tables.
(58) Tables communicate and share information, which
facilitates data searcheability, organization and reporting.
(59) A Relational
database use Structured Query Language (SQL),
which is a standard user application that provides an easy programming
interface for database interaction.
(60) A table is
a set
of data elements (values) that is organized using a model of
vertical columns (which are identified
by their name) and horizontal rows.
(61) A table
has a defined number of columns, but can have any number of rows.
(62) Each
row is identified by the values appearing in a particular
column identified as a unique key index or the key field.
(63) Columns or Fields or Attributes: A
column is a set of data values of a particular simple type, one for each row of the table.
(64) The
columns provide the structure according to which the rows are
composed.
(65) For
example, cFirstName, or cLastName are fields in a row.
(66) Rows or Records or Tuples: A row also called a Record
or Tuple
represents a single data item in
a table.
(67) In
the relational
model of a database, all data is represented in terms of tuples,
grouped into relations.
(68) In
simple terms, a database table can be visualized as consisting of rows
and columns or fields.
(69) Each
row in a table represents a set of related data.
(70) Every
row in the table has the same structure.
(71) There
are different ways to create a table: (1)
Create table in Design View (2) Use Wizard to Create Table.
(72) DATA TYPES :-Datatypes
are used to identify the type of data we are going to store in the
database.
(73)Categories of data types:- Data
types can be broadly classified into five categories:-
(1)
Numeric Types
(2) Alphanumeric
Types
(3)
Binary Types
(4) Date
Time
(5) Other
variable Types
(74) Numeric
data types are used for describing
numeric values for the field used in the table of a database.
(75) Numeric
data types in a database
can be used for storing information such as mobile number, roll number, door
number, year of school admission, true or false statements, statistical values,
etc.
(76) The different types of numeric data types available are-
1. Boolean (Yes / No)
6. Numeric
2. TinyInt (Tiny Integer)
7. Decimal
3. SmallInt (Small Integer)
8. Real
4. Integer
9. Float
5. BigInt (Big Integer)
10. Double
(77)ALPHANUMERIC TYPES:-
(1)
LongVarChar (Memo) (Long
Text)
(2)
Char (Text-fix)
(Small Text)
(3)
VarChar
(Text) (Text
of specified Length)
(4)
VarChar_IgnoreCase (Text) (Comparisions are not case sensitive)
(78)BINARY TYPES:- Binary types are used for storing data
in binary formats. It can be used for storing photos, music files or (in
general file of any format) etc.
(79)The list of different datatypes available in Binary
types are :-
1. LongVarBinary (Image)
2. Binary (Binary (fix) )
3. VarBinary (Binary)
(80) Date time data types are used for
describing date and time values for the field used in the table of a database.
It can be used for storing information such as date of birth, date of admission
etc.
The list
of different data types available in Date Time type are :-
(1)
1. Date (Stores month, day and year information)
(2)
2. Time (Store hour , minute and second information)
(3)
3. Timestamp (Stores date and time information)
SESSION 3: PERFORM OPERATIONS ON TABLE
Referential
integrity:
(81) Referential integrity is used to maintain accuracy
and consistency of data in a relationship.
(82) A relationship
refers to an association or connection between two or more tables.
(83) When
you relate
two tables, you don't need to enter the same data in separate
tables.
(84) Relationships
between tables helps to: (Advantage
or Benefits)
i)
Save time as
there is no need to enter the same data in separate tables.
ii)
Reduce
data-entry errors.
iii) Summarize data from related tables.
(85) You
can create a relationship between any two tables by selecting Relationships
option from the Tools menu.
(86) There are three types of relationships which can be created in
tables:
1.
ONE to ONE 2. ONE to MANY OR MANY
to ONE 3. MANY to MANY
(87) One to One Relationship
In this relationship, both the tables must have primary key columns.
(88) One to Many Relationship In this relationship, one of the table must
have primary key column.
(89) Many to Many Relationship In this relationship, no table has the
primary key column.
(90) MANIPULATING DATA : In a
database we can define the structure of the data and manipulate the data using
some commands.
(91) There are two types of languages:-
(1) DDL (Data Definition Language)
(2) DML (Data Manipulation Language)
(92) DATA DEFINITION / DESCRIPTION LANGUAGE (DDL) :-
It is a standard for commands that define the different structures in a database. DDL statements create,
modify and remove database objects such as tables, indexes and users.
(93)Common
DDL Statements are:-
(1)
CREATE :- Used to
create database objects.
(2)
ALTER :- Used to
modify database objects.
(3)
DROP :- Used to delete
database objects.
(94) DATA MANIPULATION LANGUAGE
(DML) :-
It is a standard for commands that enables users to access and manipulate
data in a database.
(95)
A popular data manipulation language is SQL (Structured Query Language.)
(96) Common DML Statements are:-
i)
SELECT
:- Used for retrieval of information from the database.
ii)
INSERT
:- Used for insertion of new information into the database.
iii)
DELETE
:- Used for deletion of information in the database.
iv)
UPDATE
:- Used for modification of information in the database.
99) Types
of DML:- (1) Procedural:- The user specifies what data is needed
and how to get it.
(2) Non
Procedural :-The
user only specifies what data is needed.
SESSION
4: RETRIEVE DATA USING QUERY
100)
Query is to collect specific information from the pool of data. A query
helps us join information from
different
tables and filter that information.
101)
Filtering means that the query uses criteria you
provide to hide some data and present only what you want
to see.
Creation
Of Query Using Design View Some
102)
RDBMS provide a graphical means to create queries,
but most RDBMS do not do so.
103)
That’s
where you use SQL (pronounced as “sequel”) or Structured Query Language.
104)
Query
languages are computer
languages used to make queries into databases and information systems.
105)
Queries are commands that are used to define the
data structure and also to manipulate the data in the database.
106)
A SELECT statement
retrieves zero or more rows from one or more database tables or database views.
107)
In
most applications, SELECT is the most commonly used Data Manipulation
Language(DML) command.
108)
The
SELECT statement has
many optional clauses:
(1) • WHERE specifies which rows to retrieve.
(2) • ORDER BY specifies an order in which to
return the rows.
108a) Select
* from SDetails; See all fields from table
109)
Grouping
of Data: Where command:
select * from SDetails where Color='Blue';
110)
Roll
no. arrange in Ascending order: select * from SDetails order by "Rollno" ASC;
111)
UPDATE
Command: Update
"SDetails" set "Location" = 'Bhubaneswar' where
"Rollno" = 7:
112)
CREATE
TABLE: CREATE TABLE EMP
("Emp_no" char(4), "Name" varchar(25), "Salary" Integer,
"Department" varchar(15));
113)
TO SEE FULL TABLE: Select * from EMP;
114)
INSERT
DATA: insert into
"EMP"("Emp_no", "Name",
"Salary", "Department") values ('1', 'Ram', '100',
'IT');
115)
INCREASE SALARY BY 1000: Select
"Emp_no", "Name", "Salary" +1000 from
"EMP";
116)
INCREASE SALARY BY 1000: Select "Emp_no", "Name", "Salary"
-1000 from "EMP";
117)
SALARY MULTIPLIED BY 2: Select "Emp_no", "Name", "Salary"
*2 from "EMP";
118)
SALARY DEVIDE BY 2: Select "Emp_no", "Name", "Salary" /2
from "EMP";
119)
UPDATE Command: Update "EMP" set "Name" = 'Mohan' where
"Emp_no" = 1;
120)
DELETE
DATA; delete from
"EMP" where "Name"='Ram';
SESSION 5: CREATE FORMS AND REPORTS USING
WIZARD
121)
A form provides the user a systematic way
of storing information into the database.
122)
Form is an interface in
a user specified layout that lets users to view, enter, and change data
directly in database objects such as tables.
123)
To create a form, click on
Forms option located under Database section.
124)
A report helps to display the data in a summarized
manner.
125)
Report is used to generate the overall work outcome in a clear format.
126)
You can create
reports in the database.
127)
Reports helps to get the summarized data.
Command based Questions:
Q 16 : Write an SQL query to create a table with the following
structure.
|
Field |
Type |
Ans
: CREATE
TABLE Employee ("Emp_no" char(4), "Name" varchar(25),
" Salary " Float, "Department" varchar(15)). |
|
Emp_no |
char(4) |
|
|
Name |
varchar(25) |
|
|
Salary |
Float |
|
|
Department |
varchar(15) |
Q 17 : Write SQL query
to create the Table Flight with the following structure : (2)
|
Field |
Type |
Ans
: CREATE
TABLE Flight ("Flight_ID" char(4), “Flight_Name" varchar(25), " Source " Varchar(30),
"Destination"
varchar(30)). |
|
Flight_ID |
Char(4) |
|
|
Flight_Name |
Varchar(25) |
|
|
Source |
Varchar(30) |
|
|
Destination |
Varchar(30) |
Q 18 : Consider the following table and answer the following :
|
ID |
Department |
OPD_DAYS |
Doctor_Name |
|
H201 |
ENT |
MWF |
Akaash Arora |
|
H308 |
Oncology |
TTS |
Dharma Sharma |
|
H907 |
Paediatrics |
MWF |
Sanjay Singh |
(a) Identify suitable Primary Key from the above table. Ans : ID
(b) Add a new record with the following data : (‘H608’,
‘Cardiology’, ‘TTS’, ‘Vinita Wahi’)
Ans : insert into "table"("ID","Department","OPD_DAYS","Doctor_Name")
values
(‘H608’, ‘Cardiology’,
‘TTS’,‘Vinita Wahi’)
(c) Write a select query to display records of those Doctors
whose OPD_DAYS are ‘MWF’.
Ans : select*from "table" where "OPD_DAYS" = ' MWF'
Q 19 : Write the answers based on the following table:Table:
Manger
|
Deptno |
Deptname |
Name |
City |
|
S101 |
Sales |
Pranjal Sharma |
Delhi |
|
HR404 |
HR |
Preeti Arora |
Chennai |
|
P204 |
Purchase |
Sukhmeen Singh |
Bangalore |
|
AD990 |
Admin |
Sukanya Kumar |
Mumbai |
(a)
Suggest a suitable data type for the Deptname field. Ans : varchar(25)
(b) Write a query to display all the records of the table.
Ans
: if you want to display all the data in the
table that you created in the early session, then the select statement will be:
select
* from Manger;
(c) Add a new record with the following details: (‘S106’,
‘Sales’, “Kritika Tuteja”, “Delhi”).
Ans : insert into "Manger"("Deptno","Deptname","Name","City") values (‘S106’, ‘Sales’, ‘Kritika Tuteja’, ‘Delhi’);
CBSE 10th | IT 402 Main Book | UNIT-3: RDBMS) | PYQ
|
S No |
Question UNIT-3: RDBMS) | PYQ |
Marks |
Year |
|
1 |
Mention any two integer data types of a table
field in database. 1 |
1 |
22 T2 SQP |
|
2 |
Name the relationship in which one column of
the primary key table is associated with all the columns of the associated
table and vice versa. 1 |
1 |
22 T2 SQP |
|
3 |
Define Reports of a database. 1 |
1 |
22 T2 SQP |
|
4 |
_________ means that the query uses criteria
you provide to hide some data and display only required data. a. Filtering c.
Report b. Sorting d. Forms 1 |
1 |
23 SQP |
|
5 |
Which of the following application is not
appropriate to store data about ABC Bank customers? a. Open Office Base c.
Open Office Writer b. MS Access d. MS Excel 1 |
1 |
23 SQP |
|
6 |
Multiple copies of the same file leads to
_________. a. Data Inconsistency c. Data Redundancy b. Data Consistency d.
Foreign Key 1 |
1 |
23 SQP |
|
7 |
Identify the property which help to set the
number of characters in text/ varchar type field of a table in DBMS. a. Entry
Required c. Size b. Default Value d. Length 1 |
1 |
23 SQP |
|
8 |
The length of the field value of text data
type is _____ characters by default in DBMS. a. 10 b. 25 c. 20 d. 50 1 |
1 |
23 SQP |
|
9 |
Identify the mode, where we can modify in the
structure of table? a. Datasheet view c. Design view b. Structure view d. All
of the above 1 |
1 |
23 SQP |
|
10 |
__________ store data in a single table which
is suitable to store less amount of Data. a. Flat File b. Relational c. Mini
File d. Single File 1 Page 6 of 7 |
1 |
23 SQP |
|
11 |
Akshat wants to store a huge amount
information about his firm in a database. Which type of table organization
would be most suitable for this purpose? a. Relational b. Flat File c. Either
Relational or Flat file d. Hierarchical 1 |
1 |
22 T1 SQP |
|
12 |
When primary key constraint is applied on one
or more columns then it is known as _____________ |
1 |
22 T2 PYQ |
|
13 |
A row that represents a single data item in a
table is known as _________ . |
1 |
22 T2 PYQ |
|
14 |
(a)
Database Management System |
1 |
22 T2 PYQ |
|
15 |
(b)
Primary Key |
1 |
22 T2 PYQ |
|
16 |
(c)
Numeric Data Type |
1 |
22 T2 PYQ |
|
17 |
(d)
Referential Integrity |
1 |
22 T2 PYQ |
|
18 |
Write any two examples of Database Management
Systems. 1 |
1 |
22 T2 CPYQ |
|
19 |
Name the term that is used to display the
records in ascending or descending order. 1 |
1 |
22 T2 CPYQ |
|
20 |
Define Foreign Key. 1 |
1 |
22 T2 CPYQ |
|
21 |
___________ database is a type of database
that stores data in several tables. a) Flat b) Relational c) both (a) and (b)
c) None of them 1 |
1 |
21 SQP |
|
22 |
In database _________ helps us to retrieve the
filtered data based upon some conditions. a) Forms b) Reports c) Queries d)
Table 1 |
1 |
21 SQP |
|
23 |
Rudrakshh wants that the name column of a
table must not be left blank. Help him to identify the field property for
this purpose. a) Length b) Default c) Entry Required d) Format 1 |
1 |
21 SQP |
|
24 |
___________ can be set for a field if the user
doesn't provide any value while entering the values in the table. a) Required
b) Default c) Primary Key d) Format 1 |
1 |
21 SQP |
|
25 |
Aadya wants to create a connection between two
or more tables. Suggest her the option to accomplish the task. a) Table b)
Form c) Relationships d) Sorting 1 |
1 |
21 SQP |
|
26 |
_____________ data type takes the values in
the form of 0 and 1 in the database. a) Integer b) Text c) Boolean d) Memo 1 |
1 |
21 SQP |
|
27 |
The file name extension of OpenOffice database
is .odb. (True/False) 1 |
1 |
21 CPYQ |
|
28 |
We can arrange our data in ascending or
descending order with the help of _____________ . 1 |
1 |
21 CPYQ |
|
29 |
A _________ is an organized collection of
data. You can visualize it as a container of information. 1 |
1 |
21 CPYQ |
|
30 |
Which one of the following options is
different from the other options ? 1 (A) Columns (B) Attributes (C) Tuples
(D) Fields |
1 |
21 CPYQ |
|
31 |
In this relationship, both the tables must
have primary key columns. 1 (A) One-to-many (B) One-to-one (C) Many-to-many
(D) None of the above |
1 |
21 CPYQ |
|
32 |
____________ data types are used for
describing numeric values for the field used in the table of a database. 1 |
1 |
21 CPYQ |
|
33 |
A ______________ is a set of data values of a
particular simple type, one for each row of the table. 1 |
1 |
21 CPYQ |
|
34 |
Which of the following is/are the advantage of
database ? 1 (A) Recovery (B) Backup (C) Data security (D) All of the above |
1 |
21 CPYQ |
|
35 |
____________statement is used to retrieve
records in a database. Ans Select |
1 |
20 SQP |
|
36 |
A ___________ represents a single, data item
in a table. Ans Row |
1 |
20 SQP |
|
37 |
______________ statement is used to add one or
more records to a database. INSERT OR Insert > Row OR Right-click on any Row > New
Row OR Ctrl
+ [+] |
1 |
20 PYQ |
|
38 |
______________ statement retrieves zero or
more rows from one or more database tables. Ans: SELECT OR Double click on the table Name OR Right Click on Table Name >
Open |
1 |
20 PYQ |
|
39 |
What is a primary key? |
1 |
20 PYQ |
|
40 |
a. Tuple
|
1 |
19 SQP |
|
41 |
b. Foreign Key
|
1 |
19 SQP |
|
42 |
c. DBMS |
1 |
19 SQP |
|
43 |
________ command is used to create a new table in a database. (a) New
(b) Create (c) Alter (d) Select |
1 |
18 PYQ |
|
44 |
It contain same types of data : Ans (b) Column
|
1 |
17 PYQ |
|
45 |
How Entry Required and Default Value
properties of a table field in a database are different from each other? 2 |
2 |
22 T2 SQP |
|
46 |
What is Referential Integrity? Explain its
two(any) purposes. 2 |
2 |
22 T2 SQP |
|
47 |
Identify the columns and data types of a
table: Airlines. Mention at least four columns with data type. 2 |
2 |
22 T2 SQP |
|
48 |
List Numeric and Alphanumeric Datatypes in
OpenOffice Base. 2 |
2 |
23 SQP |
|
49 |
Explain any two types of relationship that can
be created in tables. |
2 |
22 T2 PYQ |
|
50 |
What is difference between Form and Reports ? |
2 |
22 T2 PYQ |
|
51 |
Explain 'one to many' relationship to relate
two tables in a database. Support your answer with an example. 2 |
2 |
22 T2 CPYQ |
|
52 |
Define the following : 2 (a) Data Consistency
(b) Data Redundancy |
2 |
22 T2 CPYQ |
|
53 |
Ravinder wants to create a table in DBMS that
stores details of cricket players. Name any four columns along with their
data types for the same. |
2 |
22 T2 CPYQ |
|
54 |
Differentiate between Primary key and Foreign
key. 2 |
2 |
21 SQP |
|
55 |
Define RDBMS. 2 |
2 |
21 CPYQ |
|
56 |
Differentiate between Flat File and Relational
Database. Flat File: Data is
stored in a single table. Usually suitable for less amount of data. Relational
Database: Data is stored in multiple tables and the tables are linked
using a common field. Relational is suitable for medium to large amount of
data. |
2 |
20 SQP |
|
57 |
Explain two types of languages used for
creating and manipulating the data in databases. ans DDL/Data Definition
Language/ Data Description Language: which work on the structure of table and
it consist of following statements: CREATE, ALTER, and DROP. DML/Data Manipulation
language: which work on the content of table and it consist of following
statements: INSERT, UPDATE, DELETE |
2 |
20 PYQ |
|
58 |
Categorize the following commands as DDL and
DML: SELECT, ALTER, INSERT, DROP Ans: DDL: ALTER, DROP - DML: SELECT, INSERT |
2 |
20 PYQ |
|
59 |
Differentiate between (i) char and varchar
datatype Ans: char: 1. Stores exactly the length specified by user in field
definition. 2. Pads with trailing spaces for shorter strings --- varchar: It
Stores up to the specified length. 2. No
padding with extra spaces |
2 |
19 SQP |
|
60 |
(ii) DDL and DML Ans: DDL : A data definition
language or data description language (DDL) is a standard for commands that
define the different structures in a database ---- DML : A data manipulation
language (DML) is a language that enables users to access and manipulate data
in a database. |
2 |
19 SQP |
|
61 |
What is DDL ? Mention any two DDL statements. |
2 |
18 PYQ |
|
62 |
What does DBMS and RDBMS stand for ? Explain
in short. |
2 |
17 PYQ |
|
63 |
What do you mean by primary key and foreign
key ? |
2 |
17 PYQ |
|
64 |
Define the following: Table , Primary Key, Foreign Key |
3 |
20 SQP |
|
65 |
What is DDL and DML? Give one example of each.
|
3 |
20 SQP |
|
66 |
Explain
any three data types in OpenOffice base. |
3 |
20 PYQ |
|
67 |
What is RDBMS? |
3 |
19 PYQ |
|
68 |
What do you mean by DDL and DML command ? |
3 |
17 PYQ |
|
69 |
FOR VISUALLY IMPAIRED STUDENTS. Define the
following: a. Data Integrity b. Data Inconsistency c. Composite Primary Key
d. Relationship (with respect to DBMS) 4 |
4 |
22 T2 SQP |
|
70 |
Your friend owns a chemist shop, he needs to
keep records of the medicines with their id’s, date of purchase, expiry date,
price, etc. in a database program. But he does not have any knowledge about
the database. Explain to him the following to get a better understanding of
the DBMS concepts. |
4 |
23 SQP |
|
71 |
What is DBMS? Explain in brief. |
4 |
23 SQP |
|
72 |
Name any two database programs which can be
used to create a table and store the data as per the requirement. |
4 |
23 SQP |
|
73 |
Which field can be set as a Primary Key? |
4 |
23 SQP |
|
74 |
Is it possible to make more than one field as
a primary key in your table? (Yes/No). Justify your answer. 4 |
4 |
23 SQP |
|
75 |
Define the following: 1. Sorting (with respect
to DBMS) 2. Referential Integrity 3. Many-to-Many Relationship (with respect
to DBMS) 4. Foreign key (For Visually Impaired Students) 4 |
4 |
23 SQP |
|
76 |
For Visually Impaired Students : 21. Define
the following : |
4 |
22 T2 PYQ |
|
77 |
FOR VISUALLY IMPAIRED STUDENTS Define the
following : 4 (a) Relational Database Management System (RDBMS) (b) Composite
Key (c) Field (d) DDL Commands |
4 |
22 T2 CPYQ |
|
78 |
What is DBMS? Explain any two advantages of
DBMS. 4 |
4 |
21 SQP |
|
79 |
What do you mean by relationship ? Explain the
different types of relationships. 4 |
4 |
21 CPYQ |
|
80 |
Write short notes on the following : 4 (a)
Privacy (b) Data Consistency |
4 |
21 CPYQ |
|
81 |
What is database server? Explain primary key
and foreign key. |
5 |
19 PYQ |
|
82 |
Explain the following with respect to
Databases : Forms, Reports, Table 3 |
3 |
20 PYQ |
CBSE 10th Information Technology - 402 Book Solutions
Unit 3 Relational Database Management Systems(Basic)
A. Fill
in the blanks.
1. A database is an
organized collection of data.
2. A DBMS is a
software package that can be used for creating and managing databases.
3. A RDBMS is a
database management system that is based on the relational model.
4.
Three popular DBMS software are Microsoft Access, OpenOfficeBase & MySQL.
5.
A Primary Key is a unique value that identifies a row in a
table.
6.
Composite Key is a combination of one or more columns.
7.
A table is a set of data elements that is organized using a model of
vertical columns and horizontal rows.
8.
A column is a set of data values of a particular type, one for each row of the
table.
9.
A row represents a single, data item in a table.
10. Datatypes are used to identify which type of
data we are going to store in database.
11. Create table DDL command is used to create a
table.
12.
Common DDL statements are create, alter and drop.
13.
The types of languages used for creating and manipulating the data in the
Database are DDL & DML.
14.
A DDL is a standard for commands that define the different structures in a
database.
15.
A DML is a language that enables users to access and manipulate data in a
database.
16.
A Select is a part of DML involving information retrieval only.
17.
A popular data manipulation language is SQL.
18. Tables are the basic building blocks of a
database.
19.
There are three types of Relationships in a table.
20.
A form helps the user to systematically store information in the database.
21.
A form enables users to view, enter, and change data directly in database
objects such as tables.
22. SELECT statement retrieves zero or more
rows from one or more database tables or database views.
23.
By default, data is arranged in ascending order using ORDER BY clause.
24. UPDATE statement is used for modifying
records in a database.
25. DELETE statement is used to remove one or
more records in a Database.
26.
To create a form you need to select the form option available under Database
section.
27.
A query helps to collect specific information from the pool of data in the
database.
28. Report is used to display the summary of
data.
29. Forms are the interfaces with which the
user interacts.
30.
Data from multiple tables can be linked with the help of Primary Key and Foreign Key constraints.
Q1.
What does DBMS Stands for? Ans. DBMS stands for
Database Management System.
Q2.
What does RDBMS Stands for? Ans. RDBMS stands for Relational Database Management System.
Q3. How is data organized in a RDBMS? Ans. The Relational
Database Management System (RDBMS) organizes the data into tables. In tables
vertical lines are called fields and horizontal lines are called records.
Q4. State the relationship and difference between a primary and foreign key.
Ans. Primary key and Foreign key are used to relate the tables so that data can be fetched from multiple tables. We cannot enter duplicate values in Primary key while duplicate values can be entered in Foreign Key.
Q5. In how many ways tables can be created in Base? Short Answer Questions – Page 129 Ans. Tables can be created in two ways. 1. In Design view 2. Using Wizard
Q6. Why are data types used in DBMS /RDBMS?
Ans : Data types in DBMS /RDBMS are broadly
classified into five categories listed below.
(1) Numeric Types (2)
Alphanumeric Types (2) Binary
Types
(2) Date time (2)
Other Variable types
Q7. List datatypes available in Numeric Datatype?
Ans. The different
types of numeric data types are:
(1)
Integer (3) Tinyint (5)
Smallint (7) Bigint (10) Boolean
(2)
Numeric (4) Decimal (6)
Real (8) Float (11)
Double
Q8. List datatypes available in Alphanumeric Data Type?
Ans. The different
types of Alphanumeric Data Type are:
1) Longvarchar (2)
Char (3) Varchar (4)
Varchar_Ignore Case
Q9. Define the structure of a table.
Ans. A table is a set
of data elements (values) that is organized in vertical columns and horizontal rows. A table has a defined
number of columns, but can have any number of rows.
Q10. Differentiate between Tuples and Attributes of a table.
Ans. A row also called
a Record or Tuple represents a single, data item in a table. Whereas A column
is a set of data values of a particular simple type, one for each row of the
table.
Q11.
Name different Binary data types.
Ans. The different Binary data types are: (1) Longvarbinary (2) Binary (3) Varbinary
Q12. What is the file extension for
databases created using OpenOffice.Org Base? Ans. The extension is
.odb
Q13. List any three file formats that can be managed using OpenOffice.Org Base?
Ans. Three file
formats that can be managed using OpenOffice.Org Base. (1).odb (2).odf (3).odt
Q14. How many types of relationships can be created in Base? Explain each of them.
Ans. There are three types of relationship in OpenOffice Base.
ONE to ONE : In this relationship, both the tables must have primary key columns. Example: In the given tables EMP and DEPT, EMP_ID in EMP table and DEPT_ID in DEPT table are the primary keys.
ONE to MANY : In this
relationship, one of the table must have primary key column. It signifies that
one column of primary key table is associated with all the columns of
associated table.
MANY to MANY : In this
relationship, no table has the primary key column. It signifies that all the
columns of primary key table are associated with all the columns of associated
table.
Q15. What do you mean by Sorting? In how many ways it can be done?
Ans. Sorting means arranging elements in particular sequence. It can be done in two ways.
1. Increasing order 2. Decreasing Order
Q16. Explain Referential Integrity with the help of an example.
Ans. Referential integrity is used to maintain accuracy and consistency of data in a relationship. In Base, data can be linked between two or more tables with the help of primary key and foreign key constraints. for example we have two tables :
Student table has fields Admno, Name, Fname , Mname (Admno is a primary Key)
Teacher table has
fields T_id, Admno, Tname, Tsal (T_id is primary key and Admno is Foreign Key)
Both the above
tables can be linked by Common Fields ie Admno
Q17. Name DML commands.
Ans. DML stands for
Data Manipulation Language. DML Commands are :
(1)
SELECT – retrieve data from a database. (3) INSERT – insert data
into a table.
(2)
UPDATE – updates existing data within a table. (4)
DELETE – deletes all or specific records from a table.
Q18. What is the purpose of using queries?
Ans. The purpose of
using query is to collect specific information from the pool of data(TABLE). A
query also helps us to extract information from different tables.
Q19. Which clause of the Select statement helps to display specific data?
Ans. ‘Where’ clause of the Select statement helps to display specific data.
Q20. Differentiate between Where and Orderby clause of SQL statements.
Ans. Where clause helps to retrieve specific row from the table and ORDER
BY clause specifies an order in which to return the rows.
Q21. State the purpose of Update Command with the help of an example.
Ans. Update statement
is used for modifying records in a table. for example the following command
will increase the salary of all employees by Rs 2000. Update emp set sal = sal
+ 2000;
Q22. Why is there a need to create Forms? Short Answer Questions – Page 161
Ans. A form provides the user a systematic way of storing information
into the database. It is an interface in a user specified layout that lets
users to view, enter, and change data directly in database objects such as
tables.
Q23. What is the purpose of creating Reports?
Ans. A report helps
to display the data in a summarized manner. It is used to generate the overall
work outcome in a clear format. We can create reports in OpenOffice Base using
wizard.
Q24. What are the prerequisites to create a Form and Reports?
Ans. Table must be created and selected before creating forms and reports
in OpenOffice Base.
Q25. Differentiate between Forms and Reports.
Forms: A form provides an interface that allows users to enter, change and view the data in a database table. Forms are made up of elements such as textboxes and labels. We can make changes to data.
Reports: Reports are used to
present data from tables or queries in a format that can
be printed. We cannot make changes to the data.
Q26. Can a form display data from
queries? Ans. Yes
Q27. In how many ways Forms and Reports can be created in a database?
Ans. Forms and
Reports can be created in two ways: 1.
Create Form in design View 2. Create
Form using wizard
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