cbse class 10 IT 402 UNIT 3: DATABASE MANAGEMENT SYSTEM

UNIT 3: DATABASE MANAGEMENT SYSTEM

Q.1 What Do you mean by datasheet view?

Ans - It provides a visual way to create a table. It is a simple view which arranges the data in rows and columns and allows to edit the data, but not allows to change the format of the database, 

Q.2 What Do you mean by design view?

Ans - Design View It allows you to create or change the table. You can set or change every available properties for each field and can open existing tables in Design View, add, remove or change fields 

Q.3 Write steps to open table in design view.

Ans - 1. Click Table Design on the Ribbon

2. A blank table will appear in Design View.

3. Enter a name for each field down the left column.

4. To set a field as a primary key, right click on the field and select Primary Key.

Q. 4 What is the default length of varchar data type?

Ans - 50

Q.5 What is a database?

Ans - A database is information that is set up for easy access, management and updating. Computer databases typically store aggregations of data records or files that contain information, such as sales transactions, customer data, financials and product information.

Q.6 Give example of three DBMS software.

Ans - SQL,MS Access, Open Office Base 

Q.7 What is the full form of DBMS and RDBMS?

Ans -  DBMS- Database Management System 

RDBMS-Relational Database Management System

Q.8 What do you mean by DBMS?

Ans - The Database Management System (DBMS) is defined as a software system that allows the user to define, create and maintain the database and provide control access to the data.It is a collection of programs used for managing data and simultaneously it supports different types of users to create, manage, retrieve, update and store information.

Q.9 What is flat file?

Ans - A flat file database is a collection of records in which the data follows a uniform format and follows rules on value types where applicable. The database is flat because every line only holds one data input, depending on the categorization of the columns.One of the most common flat file examples is a comma-separated values (CSV) file.

Q.10 What is Relational file?

Ans - A relational database is a collection of information that organizes data in predefined relationships where data is stored in one or more tables One of the most common relational file examples is a My SQL.

Q.11 Explain primary key and foreign key.

Ans - Primary Key: A primary key is used to ensure that data in the specific column is unique. A column cannot have NULL values. It is either an existing table column or a column that is specifically generated by the database according to a defined sequence. 

A foreign key :is a column or group of columns in a relational database table that provides a link between data in two tables. 

Q.12 What is Form in MS Access?

Ans - A form in Access is a database object that you can use to create a user interface for a database application.

Q.13 What is Report in MS Access?

Ans - A report is an object in Microsoft Access that is used to display and print your data in an organized manner.

Q.14. What is SQL? 

Ans - SQL stands for Structure Query Language, It is a language that enables us to create and operate on relational databases, which are set of related information stored in tables.

Q.15 Explain DDL,DML,TCL 

Ans - DDL -Data Definition Language, allow us to perform task related to Data Definition Ex- Create, Drop 

DML- Data Manipulation Language, allow us to manipulation in database. Ex- Select, Update, Delete, Insert 

TCL- Transaction Control Language, allow us to control transaction. Ex- Commit, Rollback

Q.16  What are Different data types used in Open Office BASE. 

Ans:- i) NUMBER ii) TEXT iii) DATE iv) TIME v) BOOLEAN vi) IMAGE 

Q. 17 Difference between Char and Varchar data type 

Ans- i) Char- stores fixed length data, Varchar- store variable length data. 

        ii) char- Length varies from 0-255, Varchar- length varies from 0-65535

       iiI) char-static memory allocation, Varchar- Dynamic memory allocation

Points to Remember

• Column having no values is said to have NULL value.

• The SELECT command of SQL let you make queries on database.

• The DISTINCT keyword eliminates redundant data.

• To perform calculations, the expressions can be written along with SELECT without specifying any table name.

• The WHERE clause is used to select specific rows.

• The BETWEEN operator is used for making range checks in queries.

• The IN operator is used for selecting values form a list of values.

• The LIKE operator is used for making character comparisons using strings.

• CREATE TABLE command is used to create tables in database

• INSERT INTO command is used to insert data in the table.

• Existing data in tables can be changed with UPDATE command

• Records in a table can be deleted using DELETE command.

• ALTER TABLE command is used to alter the definition of already created tables.

• DROP TABLE command drops a table from a database.