DBMS

Data and information

Data: Data are the raw facts and figure with are isolated and uninterpreted generally represented by letter and numbers. Data undergoes processing. E.g. 32, John, 12

Information: The collection of meaningful result obtained after processing raw data. They are generated after processing. E.g. John is 32 years old and he reads in class 12.

Database: The systematic and scientific collection of data that can access quickly whenever required is called database. It is the organized way of collecting and keeping data and information. E.g. Dictionary, telephone directory, marks ledger, attendance register.

DBMS and its advantages

DBMS: DBMS stands for Database Management System which is the collection of software that is used to manage database i.e. storing, manipulating and retrieving data systematically and scientifically. It is a software used to store, process and access data and information whenever required. Eg, MS-Access, MY SQL, Oracle, dBase, Foxpro

Advantages of DBMS.

·         It helps in faster access of data.

·         It helps to reduce duplication of data.

·         It helps to provide security and privacy to data.

·         It helps in data sharing.

·         Easy to modify the data

Differentiate between database and DBMS with examples. [V.imp]

Database	DBMS
It is collection of related data.	It is a software to maintain database.
It is not secured.	It is highly secured.
Data sharing is impossible.	Data can be easily share in a network
Every DBMS has database.	Every database doesn't have DBMS.
E.g, Dictionary, telephone directory	E.g, MY SQL, Oracle.

 

MS-Access:

It is a DBMS developed by Microsoft Corporation for organizing data in the form of tables. It allows user to add, edit, delete, sort, modify, share and print records.

Feature of MS-Access.

·         Easy to store data and information.

·         Easy to enter, edit, delete and display data.

 

Objects / Element of DBMS

A) Table: The primary building block of DBMS where data are organized in the tabular form i.e rows and columns. The columns of database table are called field whereas, rows are called record. Importance of table.

·         Helps to store data in organized group.

·         Easy to sort distinct records.

Fields of table helps to store different types of datas on different topic.

B) Form: The element/object of database which allows user to enter new datas and edit the existing one easily through user friendly interface. Importance of form.

·         It provide user interface through which user can enter data.

·         It helps to modify records.

C) Query: The importance object of database which is used to retrieve/access and interpret the information according the user requirement. Importance of query.

·         It helps in faster access of data.

·         It helps to display information as per the user’s condition.

·         It helps in sorting and filtering of data.

Types of Query

1.       Select query: Used to retrieve data from one or more table depending upon the condition.

2.       Action Query: Used to make changes to records available in database. Types are

3.       Update query: Used to make global (All at once) changes to several records in different table.

4.       Append query: Used to add more records in existing one or more tables.

5.       Delete query: Used to delete one or more record from one or more tables.

6.       Make-table query: Create new table link one or more available tables in database/

D) Report: The object of database which is used to generate result after processing data in a database. It is the effective way of displaying data either in soft copy (monitor) format or hard copy (printed) format. Important of report.

·         It helps to generate summary after processing data.

·         It can be used to generate invoice, bills, statement and labels.

·         It helps to generate result in attractive and effective way.

Data types: The characteristics of field that specifies what kind of data can be stored in the given field is called  data types. 

Following are the data types used in MS-Access.

S.N	Data Type	Purpose/use	Size
1.	Text	Alphanumeric characters	0-255 characters / 256 characters
2.	Memo	Alphanumeric characters	0-65,535 characters / 65,536 characters
3.	Number	Numeric Values	Integer (2 bytes) Long integer (4 bytes)
4.	Date/Time	Date and time data	8 bytes
5.	Currency	Currency data	8 bytes
6.	Auto-number	A sequential unique serial number automatically increased by 1	4 bytes
7.	Yes/No	Logical Values	1 bit
8.	OLE object (Object Link Embedded)	Pictures, audio, video, graphics, documents	1GB
9.	Hyperlink	Link with several applications and websites	2048 characters
10.	Look Wizard	Create a field that allows to select a value.	4 bytes

 

Field properties

Field size: It is used to set the maximum size for the data stored in a given field. For eg, maximum characters (size) store in text field is 256 characters. Default field size is 50.

Format: It is used to display formatted output that means data can be display in different formats and layouts. For eg, < (Display content in lower case), > (Display content in upper case).

Input mask: It is used to specify the format in which data can be entered.

Caption: It is used to display alternate name for the field to make it more descriptive. It can contain 2048 characters.

Default value: It is the value or information that is displayed automatically when we add a new record in table for a field.

Validation rule: It enables user to limit values that can be accepted by particular field. It can contain 2048 characters.

Validation text: The message that is displayed when validation rule is violated or not followed.

Required: It is used to specify whether the data must be enter or not in the particular field.

Indexed: It is used to speed up the searching and sorting of record from the database table.

Some important terms used in DBMS

1) Extension of MS-Access database file is .MDB

2) Primary key (v.imp): The key or field that is used to uniquely identified records from the database table is called primary key. It must be unique and cannot be kept empty (null).

Importance of primary key.

·         It uniquely identifies records.

·         It helps in faster access of data.

·         It helps to prevent duplication of data.

·         It avoids empty (null) values.

·         It is used to establish table relationship.

3) Table relationship: The logical link between two or more than two tables of database using unique key fields is called table relationship. Types are: one to one, one to many, many to many.

4) Sorting: Arranging data in a particular order of field i.e. ascending or descending is called sorting. Helps in faster access of data.

5) Filtering: The process of making selection of record depending upon the supplied criteria is called filtering. Helps in faster access of data.

6) DBA: DBA stands for Database Administrator is a person or specialist who is responsible to manages and monitor overall resources and operation (such as analyzing, planning, operating, implementing and securing) associated with DBMS.

Responsibilities of DBMS.

·         Planning database activities.

·         Securing database and system.

·         Implementing modern tools and technology..

·         Maintaining database.

·         Providing user safety and privacy.

 

 1.Fill in the blanks

 

a. Data are raw facts such as text, number and symbols.

b. In database, entity may be a person or anything.

c. An example of database is dictionary.

d. An example of DBMS is MS Access.

e. A table contains a number of records using rows and columns.

f. In MS-Access, a table can be created using design view.

g. To insert logical data, we use Yes/No data type.

 

2 Write whether the following statements are true or false.

 

a. MS-Access is relational database management system. True

b. MS-Access provides a user friendly environment. True

c. In MS-Access, a report can be used to input data. False

d. Validation rule limits the data that can entered into a field. True

e. Memory consumption of Date/Time data type is 12 bytes. False

 

3. Write the technical terms for the following.

 

a. Raw facts and figures that can be entered in DBMS. Data

b. An object of MS-Access that stores data using rows and columns. Table

c. The software that can handle multiple tables and link them. MS Access

d. The key field of database that uniquely identifies records. Primary Key

e. Property of field that is used for alternate name of the field. Caption

 

4.  Answer the following questions in short:

 

What is data?

  A raw fact about anything which does not give any complete meaning is called data.

 

b. What is record?

  A group of related fields that describes a person, place, or thing is called a record. It is also called tuple.

 

c. What is maximum number of characters that can be used to define a field name?

  64 characters

 

d. Give two examples of manual database.

  A telephone directory, an organizer or printed address book are examples of manual databases.

 

e. What is default value?

  A default value is one that is displayed automatically for the field when you add a new record to the table.

 

f. What is caption?

  Caption is a field property that us used when you want to display an alternate name for the field to make the field name more explanatory.

 

g. What is index?

  Index is one of the important properties of database that speeds up searching and sorting of records using the field.

 

 

 

5. Answer  the following questions  

 

What is DBMS? Give any two examples of it.

   The software collection which helps to manage the database is called DBMS.

Examples of DBMS:

MS-Access

My SQL

 

 

b. Write any four advantages of DBMS.

-Provides an organized way of storing data

-Facilitates quick and efficient retrieval of information

-Reduces data redundancy

-Improves the consistency of data

 

c. Define data type. Write any four data types of MS-Access.

   The data type determines the kind of values that users can store in the field. Four data types of MS Access are   Text, Number, OLE , Yes/No

 

d. What is field property? Write any two common field properties of MS-Access.

   Field properties are the properties or characteristics of field that describe the characteristics and behavior of data added to that field. Two common field properties are   Field Size and Caption

 

e. Differentiate between field and record.

Field	Record
(i) A field contains data about one aspect of the table subject, such as first name or e-mail address.	(i) A record contains specific data, like information about a particular employee or a product.
(ii) A field is recognized by unique name called field name.	(ii) A field is recognized by unique key or field name called primary key.

 

f. What is table? Write different ways to create a table.

   The basic element of a database which consists of vertical columns and horizontal rows is called table. Since entire data is managed and kept in a table for the future retrieval process , it is also called the primary object of database.

Two ways to create table  

i)Design View

ii) Datasheet View

 

g. Define primary key? Write any two features of it.

   A field that uniquely identifies each record in the database is called primary key. For example: Bank account number, student registration number etc. MS-Access neither permits duplicate values in primary key not does it permit null values.

 

h. What is computerized database? Write its advantages over manual database.

   A computerized database contains electronic organized database handled by DBMS or software that allows storage of huge amount of data in a systematic way which is easy to access when required.

Advantages of Computerized database:

- Provides an organized way of storing data

- Facilitates quick and efficient retrieval of information

- Reduces data redundancy

- Improves the consistency of data

- Allows sharing of data

 

i.Write any four sub data types of number data type.

   Integer , Long Integer, Single , Double

 

j. What is sorting? Write any two advantages of sorted database.

   A process of arranging the data items in some sequence or order according to the given criteria is called sorting. It can arrange data in ascending or descending order.

 

Two advantages of sorting:

i)Sorting helps to find the data quickly.

ii) Sorting helps to reduce data redundancy. 

Queries

 

1.      Fill in the blanks:

 

a. Query allows to display, delete, and update data.

b. Action query makes permanent change in the table of data.

c. In MS-Access only table object stores data.

d. Form allows users to view, edit and enter new records.

e. To find the hard copy output, we use report

 

2.      State whether the following statements are true or false.

 

a. Memory consumption of Yes/No data type is 1 byte. False

b. MS-Access is a product of Microsoft Corporation. True

c. MS-Access is RDBMS.True

d. Update query can be used to insert calculated data to the table. True

e. Delete query is an example of non-action query. False

f. Form makes data entry and editing easier. True

 

3.      Write the technical terms for the following:

 

a. Object of MS-Access that stores data Table

b. Data type that inserts numbers automatically Autonumber

c. Arrangement of data in ascending or descending order Sorting

d. Key field that uniquely identifies the records Primary Key

e. Object of MS-Access which is used to view, edit and insert data Form

f. Data type of MS access that consumes least amount of memory Yes/No

 

4.      Answer the following questions in short:

 

(a) What is a query?

  An important object of database that allows user to view data and change data of the database with the different criteria is called query.

 

(b) What is a report?

  A report is one of the components of MS-Access. It is used to display the data as per the format selected by the user. It is a summary of the data contained in one or more tables on queries.

 

(c) What is validation rule?

  Validation rule limits the values that can be entered into a field.

 

(d) What is a caption?

  Caption is a field property that is used when you want to display an alternate name for the field to make the field name more explanatory.

 

(e) What is record?

  A group of related fields that describes a person, place, or thing is called a record. It is also called tuple.

(f) What is memo data type?

  Memo is a data type of MS Access which can store the alphanumeric characters from 0-65535 characters.

 

5. Answer the following questions :

 

(a)Define action query? Give two examples of it.

  Action query performs an action on data in a table. You can use an action query to insert new records, to update existing records, or to delete existing records. Action query makes permanent change in the table of data. Example: Changing name spelling of a student, updating the computer marks etc.

 

(b) What is a form? What are the different ways to create a form?

  Form is a database object used primarily to displays records on screen, to make it easier to enter new records and to make changes to the existing records. Two ways to create a form : Form design and Form Wizard

 

(c) Write any two uses of a form.

 (i) Form is used to view the records individually.

(ii)Form helps to add new records.

 

(d) What is a report? Write its use.

  A report is one of the components of MS-Access. It is used to display the data as per the format selected by the user. It is a summary of the data contained in one or more tables on queries. Uses of Report: (i) Report is used to get the summary or result. (ii) Report helps to print the output in an effective way.

 

(e) Differentiate between action query and non-action query(select Query)?   

Action Query	Non-action Query
(i) Action query makes permanent change to database.	(i) Non-action query does not make any changes to database.
(ii) While running action query alert message appears.	(ii) While running non-action query no alert message will appear.