Lesson
No. 5 Database Concepts using LibreOffice Base
Textbook
Exercises
Fill ups
1. __________
is a collection of related data.
Ans.
Database
2. Queries
are used to _______ information from database.
Ans. retrieve
3. The
representation of data in printed form is called as __________
Ans. Report
True or
False
1. Form is used to collect the data from the
user. TRUE
2. Menu bar is present below Title bar.
TRUE
3. Columns are called as records. FALSE
MCQ (
select 1 correct answer)
1. Rows in Base are called as _____
Ans. Records
2. File extension of Base is _______
Ans. .odb
Answer in
Brief
1. Define
Database
Ans.
Database is a collection of related data items stored in an organized manner. A
database consist of different objects like table, query, form and report.
2. What
is a query?
Ans. A Query
is a question asked within the database environment. Query is used to retrieve
records from the table. Query displays subset of data contained in various
tables of database.
3. Define
Report.
Ans. The
presentation of information in an organized and readable format as per the user’s
requirement known as report. Report is the representation of data in printed
form. Various complex reports can be generated that can help in taking
decisions by the management.
4.
Explain working area of Base.
Ans. The
area below the standard toolbar is called as working area. It is divided into
two panes – Left pane and right pane. Left pane displays name of database
objects like tables, queries, forms and reports. Right pane display activities
related to that particular object.
Match the following
1.
Query - Retrieve data from
database.
2.
Report - printed form of data.
3.
Form - Collect information from
user.
4.
Table - Collection of related
data.
Additional Exercises
Answer in brief
5.
Define Data and Information
Ans. Data means all kinds of facts,
figures and details related to people, places, things or events.
Information is the result obtained
from processing.
6. What is a Table?
Ans. Table is a basic unit for
storing data in database. Tables are organized in the form of rows and columns.
User can insert, edit and delete records from table.
7. Define Entity
Ans. An entity is any real world
object about which data is to be stored. Each entity has collection of
attributes associated with it.
An attribute is the property of
entity. It is stored in the form of columns. Example – Student entity has
attribute s like roll number, name, address, standard, date of birth, etc.
8. List the data type available in
Base.
Ans. The data types can be divided
into categories as alphanumeric, numeric, calendar and binary type.
Numeric
data types |
Alphanumeric
data types |
Calendar(Date
and Time) data types |
Binary
data types |
TINYINT |
CHAR |
DATE |
Image(LONGVARBINARY) |
BIGINT |
VARCHAR |
TIME |
VARBINARY |
NUMERIC |
VARCHAR_IgnoreCase |
TIMESTAMP |
BINARY |
DECIMAL |
|
|
BOOLEAN
|
INTEGER |
|
|
|
SMALLINT |
|
|
|
FLOAT |
|
|
|
REAL |
|
|
|
DOUBLE |
|
|
|
9. What is a Form?
Ans. A form is an object which allows
entering the data and editing or deleting existing data in the table. Form is
used to collect the data from the user. It consists of format, style and
widgets like radio button, list boxes that provides easy and systematic way to
insert records in the table.
10. What is Data model?
Ans. Data model defines how the
logical structure of a database is modeled. Data model defines how data is
connected to each other and how they are processed and stored inside the
system.
There are types data model such as
relational data model, network data model, hierarchical data model,
object-oriented data model, entity relationship data model, etc.
11. What is Relational Data Model?
Ans. In relational data model, data in a database
is stored in structured format, using rows and columns called tables. It is
relational because the values within each table are related to each other.
Tables may also be related to other tables. In relational model, tables are
called relations that store data for different columns.
12. Define Attribute, Domain, Tuple,
Degree, Cardinality
Ans.
Attribute – Characteristic or parameters for
which data are to be stored in a relation. The columns of a relation are the
attributes which are also referred as fields.
Domain – It is a set of values from which
an attribute can take a value in each row. A data type is used to specify
domain for an attribute.
Tuple – Each row of data in a relation
(table) is called a tuple. A tuple is a relationship between the n related
values.
Degree – The number of attributes in a
relation is called the Degree of the relation.
Cardinality – The number of tuples in a relation
is called the Cardinality of the relation.
13. Define the following
a) Candidate Key – A relation(table) can have one or
more attributes(columns) that takes unique values. The attributes can be used
to uniquely identify the tuples in the relation are called candidate keys.
b) Primary Key – The attribute used to uniquely identify
the tuples(rows) in relation is called the primary key of that relation.
c) Foreign Key – A foreign key is used to represent
the relationship between two relations(tables). A foreign key is an attribute
whose value is derived from the primary key of another relation.
14. Explain the types of relationships
in relational database design.
Ans. The types of relationships are
as follows :
a) One-to-One (1:1) – In one-to-one relationship, a row in table A
can have only one matching row in table B.
b) One-to-Many (1:M) – In one-to-many relationship, a row
in table A can have one or many matching
rows in table B.
c) Many-to-Many (M:M) – In many-to-many relationship, a
row in table A can have many matching
rows in table B and vice versa.
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