CBSE Class 12 Informatics Practices — NCERT Solutions

An RDBMS is a Relational Database Management System. It stores data in the form of related tables (relations) and manages relationships among them.

Two examples are MySQL and Oracle.

i) ORDER BY: It is used to sort the records in a query result in ascending or descending order.

ii) HAVING: It is used to apply conditions on grouped records when using GROUP BY.

A Series is a one-dimensional array in Pandas that stores a sequence of values of any data type and has index labels for each value.

Differences:

• 1-D array (NumPy ndarray): stores elements in a one-dimensional form, but uses only integer positions for indexing.
• List: a general Python collection; it does not provide Pandas-style labeled indexing and built-in data analysis methods.
• Dictionary: stores key:value pairs, while a Series stores values with an index. A Series can be created from a dictionary, but it is not the same thing.

A DataFrame is a two-dimensional labelled data structure like a table. It contains rows and columns, and each column may have a different data type.

Difference from a 2-D array:

• A 2-D array usually stores homogeneous data and is accessed mainly by numeric positions.
• A DataFrame can store different data types in different columns and uses row and column labels for easier access and analysis.

The statement to install the MySQL connector pymysql is:

pip install pymysql

pivot() is used to reshape a DataFrame when the entries for the specified index and columns are unique. It rearranges data from rows into a new table.

pivot_table() works like pivot(), but it can handle duplicate entries by applying an aggregate function such as mean, sum, max, or min. The default aggregate function is mean.

So, the main difference is:

• pivot() does not work with duplicate values for the chosen index/columns.
• pivot_table() can reshape data even when duplicates are present, by aggregating them.

The Matplotlib library is used for creating static, animated, and interactive 2D plots or figures in Python.

a) Data are divided into smaller chunks called packets.

b) The set of rules that decide the functioning of a network is called Ethernet.

c) A LAN can be extended up to a distance of 1 km.

d) The router connects a local area network to the internet.

e) The tree or hybrid topology is of hierarchical nature.

f) URL is a standard naming convention used for accessing resources over the Internet.

g) A website is a collection of related web pages.

h) A web server is a computer that provides services to other programs or computers.

Revaan is using Atharv’s logged-in email account as if he were Atharv and sending messages in Atharv’s name. This means he is misusing another person’s identity to act online, which is identity theft. It is not just hacking because he did not break into the system; he used the already open account.

Project I: Online Shopping Platform

Murugan’s online shopping platform APPAREL EASY should be designed to store and analyse merchandise and sales data using Python Pandas.

Main idea

• The platform has two broad categories: Men and Women.
• Under each category, the sub-categories are Clothing, Footwear, Accessories.
• Two mega events are to be handled:
• Festive Sale (FEST): from a month before Diwali to Christmas
• End of Season Sale (EOS): in February and August
• Records must be maintained for:
• monthly revenue generation sales
• category-wise sales
• discounts offered by manufacturers, payment sites, or portal promotions
• customers visiting the site and customers placing orders

Required data fields

The details of Men’s and Women’s apparels should be stored in a data file with fields such as:

• Apparel Code
• Name
• Category
• Size
• Price
• Customer Name
• Payment Mode
• Discount Code

Category-wise items

• If Category = Men, apparels may include:
• Men’s Trousers
• Men’s Shirt
• Men’s Jeans
• Men’s T-shirt
• If Category = Women, apparels may include:
• Skirts
• Top
• Pants
• Jeans
• Kurta

Payment mode rules

• If Payment Mode is Credit Card or Debit Card:
• credit/debit card number
• name
• CVV
• validity

should be entered.

• If Payment Mode = COD (Cash on Delivery), then no card details are required.

Sale selection and discount

• Merchandise to be put on sale should be selected randomly.
• The selected merchandise should be not more than 70% of the total merchandise.
• Discount code can be:
• FEST → 10% discount
• EOS → 15% discount

What should be implemented

• Visualise the data structure as required.
• Implement the system using Python Pandas.
• Design software to store merchandise details and place them online for sale.
• Maintain records of:
• customers visiting the e-commerce site
• number of customers placing orders
• Plot the collected data appropriately so that Murugan can make better marketing and promotion decisions.

So, in short, the project is about building a data-driven e-commerce management system for apparel sales with customer tracking, discount handling, and graphical analysis.