SQL - Group By, Order By, Having

Full Name

Email ID

Student Id (Id No.)

Group By is used to

• Arrange identical data into groups

• Summarize data in the table

• Is used to create ranges

• applies aggregate and ranking functions over a particular group

What is the correct order of Execution of SQL Commands:

• From->Where->Group By->Having->Select->Order By

• Select->Where->Having->Group By->Order By->From

• Group By->Having->Select->Order By->From->Where

Which query will summarize the total number of matches played by each country?

• Select country , sum(`matches played`)

  From Games

  Group By Country;

• Select country, count(`matches played`)

  From Games

  Group By Country;

• Select players, country, sum(`matches played`)

  From Games

  Group By `matches played`;

• Select *

  From Games

  Group By Country;

What will this query return:

SELECT DISTINCT Country FROM Customers;

• Returns a list of all countries

• Returns a list of all customers

• Returns total number countries

• Return a list of all countries which appeared in the table just once

What does UNIQUE keyword do?

• Returns only those values which appeared only once in the column

• Returns list of values without repetition

• Unique Keyword is used at the time of table creation to prevent user from inserting duplicate value

• UNIQUE keyword allows duplicate values in a column

Complete the query by dropping the correct answers from the options given.

Q: List the number of customers in each country.

Query: SELECT ​​Country, (a)   (CustomerID)

FROM Customers

​ (b)   By ​ (c)   ;

• count
• Group
• country
• Order By
• CustomerID
• Sum

Complete the query by dropping the correct answers from the options given.

Q: List the number of customers in each country, ordered by the country with the most customers first.

Query: SELECT ​Country, (a)   (CustomerID), Country FROM Customers

​ (b)  

ORDER BY​ (c)   ​ (d)   ;​

• count
• Group By Country
• desc
• DISTINCT
• ASC
• Unique
• Group By CustomerID
• count(Country)