The raw facts constitutes data. The facts may be related to any person, place, activity or things.

It
may be stored in the form of text, graphics, audio or video.

Information is the processed or organized form of data. If data is not correct or accurate, the
information obtained by processing such data may not be correct.

A database is a collection of logically related data items stored in an organised manner.

The software that is used to create, update and retrieve data is known as database management
system (DBMS). It facilitates planning and maintenance of the database for the user

Examples:MS Access, Open Office Base or LibreOffice Base, MySQL

Advantages of DBMS:

• Organised Storage – The data in the database is stored in an organised manner, so that retrieval of
the required data is fast and accurate.

• Data Analysis – A database helps in analysis of data based on certain criteria. It is easy to find out
maximum or minimum value, average or mean using a database.

• Data Sharing – If the same data set is required for different applications then the database can be
shared with other applications. Hence using a database means making once and using it repeatedly
for multiple applications.

• Minimal Data Redundancy – In the event of requiring the same data field in several tables the data
field might get repeated in number of tables. This is called as data redundancy. This can be reduced
by using DBMS tools.

• Data Consistency: By minimizing data redundancy, the chances of storing inconsistent data are
reduced. For instance, if a student's name is changed, a DBMS can automatically reflect this change
in all related tables by setting a relation between them, preventing the name from being updated in
one table but not another.

A data model is the structure of a database that describes the manner in which data will be stored
and retrieved.

Hierarchical Data Model

In this model the data is organized into a tree like structure. The data is stored in the form of records.
A record is a collection of fields and its data values. All these records are linked to each other at
various levels, thereby forming a hierarchy.

Network Data Model

Hierarchical Data Model In this model, multiple records are linked to same master file. It is also
considered as an inverted tree where master is present in the bottom of the tree and the branches
contain information linked to the master.

Relational Data Model Project

This data model is based on the principle of setting relationships between two or more tables of the
same database. It is the most commonly used database model.
proposed in 1970 by E. F. Codd. Relational database model is the most common type of database
model. The data elements are stored in different tables made up of rows and columns. The data in
different tables are related through the use of common fields. So relations are set between tables
based on common fields. That is why this model is termed as relational database model.

TERMINOLOGY

Entity – It is a real world object about which information is to be stored in a database These details
associated with the entity are called attributes. Each entity is a collection of these attributes
associated with it.

Table – A table is a collection of logically related records. It is organised as a set of columns, and can
have any number of rows.

Field or Columns or attributes – A field is the smallest entity in the database. A collection of fields
make a record, a collection of records make a table and a collection of tables make a database. Fields
are individual record characteristics and are presented as columns within a table. Data values are
stored in a database as fields. A field holds the data values of one type of data for several persons.

Data Values – Data values are the raw data represented in numeric, character or alphanumeric form.

Record or Row – The data values for all the fields related to a person or object is called a record. It is
presented as rows within a table. A record holds the data values of all the fields for a single person or
object in a table.

Relational Database – A relational database is a collection of related tables

PRIMARY KEY:

A primary key or simply a key is

a field that uniquely identifies a row in a table.

•It acts as a unique identifier for the table.

•The value of the primary key must be unique for each different row. This means no two rows in the
table can have the same value for the primary key at any time.

•Also, the primary key field cannot be left blank

If, in a table we use more than one fields to identify a record, it is known as a composite key..

Foreign Key – If a field or a combination of fields of one table can be used to uniquely identify
records of another table, then that particular field is known as the foreign key. This foreign key helps
to build a relation between two tables

Candidate Key – All the field values that are eligible to be the primary key are the candidate keys for
that table. Such fields can neither be left blank nor can have duplicate values.

Alternate Key – Out of the candidate keys, one or two are made as primary keys. The others are the
alternate keys.
An object in a database is a structure or a feature that is used to store, represent or retrieve data.

Table – As mentioned before, a table is the basic unit of any DBMS. The data is first stored in tables in
row and column format. A column represents a field or an attribute while a row represents a record.

Forms – A form is a feature of a database using which we can enter data in a table in an easy and
user friendly manner. A form consists of text boxes, list boxes, check boxes ,etc. that give a user
friendly interface for entering data. The data entered through the forms is stored in tables.

Reports – The output of a query may be displayed in the form of reports. The usual result of the
query is in the form of rows and columns. But if we want the report to be formal and in proper
layout, then we can use the Reports feature of RDBMS.
Queries – A query is used to retrieve the desired
information from the database. In simple terms,
it is a question asked from the database
NEXT CHAPTER:

Data Types

The nature of data to be entered for various fields are of different types. A data type refers to the
type of data that will be stored in that particular field.

TYPES OF DATA TYPE:

Text Data Type – The text data is a combination of letters, numbers or special characters. No
arithmetic calculations can be performed on text data

Numeric Data Type – Numeric data types consists of numbers. The numbers can be integer or real
numbers on which any type of arithmetic calculations can be performed
Currency Data Type – The currency data type indicates the monetary values and can be stored using
currencies of various countries.

Date Data Type – This data type is used to indicate dates and time The data and time can be stored in
various formats:

Boolean – In Boolean data type there can be only two values- True or False. This also can be given in
multiple formats like Yes/No, True/False, On/Off.

Binary – The Binary data type used to store digitized images and sounds that comes as long string of
zeros and ones.

USING LIBREOFFICS BASE

Start > LibreOffice or double click on the LibreOffice icon on the desktop or Select Base Database
option from the bottom left panel. If we register the database, then our database is made public and
hence can be accessed by other people. click and select the radio button with option, ‘No, do not
register the database’.

The database in Base is saved with an extension .odb.

The various components of the Base User Interface are discussed below:
Title Bar – The title bar displays the name of a database and an application in which it is
made. The windows buttons to maximize, minimize or close the window are located on the
right corner of the title bar.
Menu Bar – The menu bar appears below the title bar. It consists of seven menu items – File,
Edit, View, Insert, Tools, Window and Help
Standard Toolbar – It is located below the menu bar. It is used to access frequently used
tools
Status Bar – It is located at the bottom of the interface window. It displays information about
the type of view of the object in the database.
Database Pane – The database pane is located on the left side of the window.

Opening a Database
File > Open
Ctrl+O
A table in LibreOffice Base can be created using a wizard or using the Design view.
At the time of creating the database:
Create tables using the table wizard
After creating the database:
Use Wizard to create a table

WIZARD:
Table Wizard of Base consists of ready-made tables. Click the Sample tables list box and
select any one table
STEP 1
FIELD SELECTION FORM AVAILBLE FIELDS
Available Fields. The required fields from Available fields box can be shifted one by one to
Selected fields box using > button as shown in. You can select all the fields from Available
fields to Selected fields in one stroke by clicking on >>
STEP 2-Set Types and Format
STEP 3- Set Primary Key
FINAL STEP-The 3 choices (by default the insert data immediately option is selected)
Then....... Now it will allow you to enter the data as per the selected fields
Problem in using wizard
Creating the table using wizard restricts us to use the same fields in the per-designed tables.

DESIGN VIEW:
advantage of design view
Design View gives us more flexibility to do our work.
STEP 1:
Select the option "Create Table in Design View"
The screen is broadly divided into two sections or horizontal panes. The upper half consists
of a grid structure with three columns Field Name, Field Type and Description
Field Name – It is the name of the field assigned at the time of creation of
Field Type – It allows to assign a data type to the field.
Description – It allows to describe the purpose of the field. It is not the part of database
table
The Field Properties pane is located at the bottom half of the window. It displays the field
properties assigned by the database designer its used to control and validate the data that is
to be entered
ENTERING DATA
Step 1. Type the first field name in the Field Name column.
Step 2. The Field Type column contains a list box. As you click on the down arrow, it appears
and we can select the desired data type from the list box. Select the datatype (Varchar).
Step 3. Observe that certain properties appear in the Field Properties Pane as the data type
is selected. Some of the properties are Entry required, Length, Default valueSelecting data
type for field Format example. Set the desired properties for the entered field.
Step 4. Press Tab key to move to the next column. Add any description if you want in the
third column.
Step 5. Once the properties for the field are set, press Tab key to move to next row.
Setp6: repeat the process for rest of the rows

Setting the Primary Key

To set primary key right click on the desired field name. Then a pop-up menu shows up and,
in that select, primary key.

SAVE:
Press Ctrl + S

File > Save As

File-> Save option.

TO SET COMPOSITE KEY

Keep the Ctrl key pressed and then click on multiple fields to select them. After right click on selected fields and
choose Primary Key

ENTERING DATA IN TABLE

Entering Data in a Table To enter data in the table, double click on the created table Events icon in the Tables
Object Area

we can open the table by right clicking on the desired table and then selecting the Open option from the drop
down menu

What if the number of fields in the table are more?

number of fields are more and cannot fit in the single row, you can use the horizontal scroll bar to view all the
fields

Use Tab to move to next field. Once all the data values are entered for a single record, the cursor moves to the
next record. This process is called as data entry

NAVIGATION

The black pointing arrow ( )just before the field name is the record pointer. To navigate through various records
of the table, we use the navigation box present at the bottom of the datasheet window
The various components of Navigation Box are as follows:

Record Selector Box – This is the text box where the currently active record number is displayed.

Navigation Buttons – These are used to scroll vertically in the table.

DELETIBG DATA

Pressing the Del key from the keyboard or selecting the Delete Record option from the Edit menu right clicking
on the record and clicking on the Delete Rows option from the pop up menu. Attempting to delete the record
will display the Confirmation box as shown in. Clicking on Yes button will finally delete the record, while clicking
on the No button will not delete the record.

This process of arranging the records in particular order on any filed is called as sorting. select the field on
which you want to sort.

SORTING

tool bar click Sort Ascending icon if the table has to be sorted in ascending order of selected field. Alternatively
select Sort Descending to sort more than one field click the sort of icon before selecting any fields, then it will
appear a dialog box in which you can select multiple fields and to be sorted ascending or descending order,
then confirm by pressing OK

to sort more than one field click the sort of icon before selecting any fields, then it will appear a dialog box in
which you can select multiple fields and to be sorted ascending or descending order, then confirm by pressing
OK

File > Close or click on the cross (x) button