Course Summary

Summary

In the last part of the course, you explored two essential SQL skills: filtering data and using aggregate functions. Mastering these topics is crucial for analyzing and summarizing information stored in databases.

Filtering data: use the WHERE clause to retrieve only the rows that meet specific conditions; this helps you focus on relevant information and answer precise business questions;
Aggregate functions: apply functions like COUNT, SUM, AVG, MIN, and MAX to calculate totals, averages, and other summary statistics; these are valuable for producing reports and insights from large datasets.

You typically use filtering and aggregate functions together to generate meaningful summaries, such as finding the average population for countries in a specific region or identifying the largest country by surface area. These skills are fundamental for anyone working with data in SQL.

1. Which clause is used to filter rows in a SQL SELECT statement before any grouping or aggregation?

2. Which of the following is an aggregate function in SQL?

3. Write a SQL query to find the total population of countries in Asia using the SUM aggregate function. Only include countries where the continent is Asia.

4. Write a SQL query to find out how many countries have a population greater than 10 million. Use the COUNT aggregate function and the WHERE clause.

5. Which aggregate function returns the average value of a numeric column in SQL?

Which clause is used to filter rows in a SQL SELECT statement before any grouping or aggregation?

Select the correct answer

HAVING

GROUP BY

WHERE

ORDER BY

Which of the following is an aggregate function in SQL?

Select the correct answer

COUNT

IF

JOIN

SELECT

Write a SQL query to find the total population of countries in Asia using the SUM aggregate function. Only include countries where the continent is Asia.

SUM(Population) Country Continent = 'Asia';

322880000

Click or drag`n`drop items and fill in the blanks

Write a SQL query to find out how many countries have a population greater than 10 million. Use the COUNT aggregate function and the WHERE clause.

SELECT COUNT(*)FROM CountryPopulation > 10000000;

Click or drag`n`drop items and fill in the blanks

Which aggregate function returns the average value of a numeric column in SQL?

Select the correct answer

COUNT()

MAX()

AVG()

SUM()

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How can we improve it?

Thanks for your feedback!

Section 5. Chapter 9

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Course Summary

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Summary

Filtering data: use the WHERE clause to retrieve only the rows that meet specific conditions; this helps you focus on relevant information and answer precise business questions;
Aggregate functions: apply functions like COUNT, SUM, AVG, MIN, and MAX to calculate totals, averages, and other summary statistics; these are valuable for producing reports and insights from large datasets.

1. Which clause is used to filter rows in a SQL SELECT statement before any grouping or aggregation?

2. Which of the following is an aggregate function in SQL?

3. Write a SQL query to find the total population of countries in Asia using the SUM aggregate function. Only include countries where the continent is Asia.

4. Write a SQL query to find out how many countries have a population greater than 10 million. Use the COUNT aggregate function and the WHERE clause.

5. Which aggregate function returns the average value of a numeric column in SQL?

Which clause is used to filter rows in a SQL SELECT statement before any grouping or aggregation?

Select the correct answer

HAVING

GROUP BY

WHERE

ORDER BY

Which of the following is an aggregate function in SQL?

Select the correct answer

COUNT

IF

JOIN

SELECT

Write a SQL query to find the total population of countries in Asia using the SUM aggregate function. Only include countries where the continent is Asia.

SUM(Population) Country Continent = 'Asia';

322880000

Click or drag`n`drop items and fill in the blanks

Write a SQL query to find out how many countries have a population greater than 10 million. Use the COUNT aggregate function and the WHERE clause.

SELECT COUNT(*)FROM CountryPopulation > 10000000;

Click or drag`n`drop items and fill in the blanks

Which aggregate function returns the average value of a numeric column in SQL?

Select the correct answer

COUNT()

MAX()

AVG()

SUM()

Everything was clear?

How can we improve it?

Thanks for your feedback!

Section 5. Chapter 9