GROUP BY with multiple columns in MySQL - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to group the sales by both city and product.

MySQL

SELECT city, product, SUM(sales) FROM sales_data GROUP BY [1];

Drag options to blanks, or click blank then click option'

Acity, product

Bproduct

Csales

Dcity

Attempts:

3 left

💡 Hint

Common Mistakes

Grouping by only one column when two are needed.

Using the sales column in GROUP BY instead of city and product.

The GROUP BY clause groups rows that have the same values in both city and product columns, so the sum of sales is calculated for each unique city-product pair.

2fill in blank

medium

Complete the code to select city and product, and count the number of sales entries for each group.

MySQL

SELECT city, product, COUNT(*) FROM sales_data GROUP BY [1];

Drag options to blanks, or click blank then click option'

Acity, product

Bcity

Csales

Dproduct

Attempts:

3 left

💡 Hint

Common Mistakes

Grouping by only one column and getting incorrect counts.

Using COUNT(column) instead of COUNT(*) which counts all rows.

Grouping by both city and product allows counting how many sales entries exist for each unique combination.

3fill in blank

hard

Fix the error in the GROUP BY clause to correctly group by city and product.

MySQL

SELECT city, product, AVG(price) FROM sales_data GROUP BY [1];

Drag options to blanks, or click blank then click option'

Aprice

Bcity product

Cproduct city

Dcity, product

Attempts:

3 left

💡 Hint

Common Mistakes

Forgetting commas between columns in GROUP BY.

Grouping by a column not in the SELECT list.

Columns in GROUP BY must be separated by commas. Writing them without commas causes a syntax error.

4fill in blank

hard

Fill both blanks to group sales by city and product and order the results by city ascending.

MySQL

SELECT city, product, SUM(sales) FROM sales_data GROUP BY [1] ORDER BY [2] ASC;

Drag options to blanks, or click blank then click option'

Acity, product

Bsales

Ccity

Dproduct

Attempts:

3 left

💡 Hint

Common Mistakes

Ordering by a column not selected or grouped.

Grouping by only one column when two are needed.

The query groups by both city and product and orders the results by city in ascending order.

5fill in blank

hard

Fill all three blanks to select city and product, count sales entries, and filter groups having more than 5 entries.

MySQL

SELECT [1], [2], COUNT(*) FROM sales_data GROUP BY [3] HAVING COUNT(*) > 5;

Drag options to blanks, or click blank then click option'

Acity

Bproduct

Ccity, product

Dsales

Attempts:

3 left

💡 Hint

Common Mistakes

Using WHERE instead of HAVING to filter aggregated results.

Not grouping by all selected columns.

The query selects city and product, groups by both columns, and filters groups with more than 5 sales entries using HAVING.