CBSE 10th Information Technology - 402 Book Solutions ( Unit 3 Database Management Systems(Basic) )

 
CBSE 10^th 
Information Technology - 402 
Book Solutions
Unit 3 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.
 
Short Answer Questions – Page 129
Q5. In how many ways tables can be created in Base? 

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
3)    Binary Types    
4)    Date time
5)    Other Variable types

 

Q7. List datatypes available in Numeric Datatype? 

Ans. The different types of numeric data types are:
1)    Boolean
2)    Tinyint
3)    Smallint
4)    Integer
5)    Bigint
6)    Numeric
7)    Decimal
8)    Real
9)    Float
10) 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 :
SELECT – retrieve data from a database.
INSERT – insert data into a table.
UPDATE – updates existing data within a table.
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 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;
 
Short Answer Questions – Page 161
Q22. Why is there a need to create Forms?

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	Reports
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.	Reports are used to present data from tables or queries in a format that can be printed.
We can make changes to data.	We can not 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