Commerce (English Medium) Class 12 - CBSE Important Questions

Based on the table STUDENT given here, write suitable SQL queries for the following:

1. Display gender-wise highest marks.
2. Display city-wise lowest marks.
3. Display the total number of male and female students.

Discuss the significance of Group by clause in detail with the help of a suitable example.

Write suitable SQL query for the following:

Display 7 characters extracted from the 7^th left character onwards from the string ‘INDIA SHINING’.

Write suitable SQL query for the following:

Display the position of occurrence of the string ‘COME’ in the string ‘WELCOME WORLD’.

Write suitable SQL query for the following:

Round off the value 23.78 to one decimal place.

Write suitable SQL query for the following:

Display the remainder of 100 divided by 9.

Write suitable SQL query for the following:

Remove all the expected leading and trailing spaces from a column userid of the table ‘USERS’.

Explain the following SQL function using a suitable example.

UCASE()

Explain the following SQL function using a suitable example.

TRIM()

Explain the following SQL function using a suitable example.

MID()

Explain the following SQL function using a suitable example.

DAYNAME()

Explain the following SQL function using a suitable example.

POWER()

Shreya, a database administrator has designed a database for a clothing shop. Help her by writing answers to the following questions based on the given table:

1. Write a query to display cloth names in lowercase.
2. Write a query to display the lowest price of the clothes.
3. Write a query to count the total number of clothes purchased in medium size.
   OR
   Write a query to count the year-wise total number of clothes purchased.

To display the last five rows of a series object ‘S’, you may write ______

Which of the following statement will import pandas library?

Which of the following can be used to specify the data while creating a DataFrame?

Assertion (A): DataFrame has both a row and column index.

Reasoning (R): A DataFrame is a two-dimensional labelled data structure like a table of MySQL.

Write a program to create a series of objects using a dictionary that stores the number of students in each house of class 12D of your school.

Note: Assume four house names are Beas, Chenab, Ravi, and Satluj having 18, 2, 20, and 18 students respectively and pandas library has been imported as pd.

What will be the output of the following code:

>>>import pandas as pd
>>>A = pd.Series(data = [35, 45, 55, 40])
>>>print(A > 45)

Carefully observe the following code:

import pandas as pd
Year1 = {'Q1':5000,'Q2':8000,'Q3':12000,'Q4': 18000} Year2 = {'A' :13000,'B':14000,'C':12000}
totSales = {1:Year1,2:Year2}
df = pd.DataFrame(totSales)
print(df)

Answer the following:

1. List the index of the DataFrame df
2. List the column names of DataFrame df.