Skip to main content
Practice

Count Transactions by Customer

You've been asked to review the activity level of each customer by counting how many transactions they've made.

This kind of summary is useful when identifying frequent users or analyzing behavior across a large dataset.

To solve this, you'll use COUNT() along with GROUP BY to collapse the data into customer-level counts.


Task​

From the transactions table in the bank_transactions.sqlite database, display:

  • customer_id
  • transaction_count (use an alias for COUNT(*))

Sort the results by transaction_count in descending order to highlight the most active customers first.


How to solve it​

Write a SQL query that counts how many transactions each customer has made.

Group the results by customer_id, and use ORDER BY to sort from most to fewest transactions.

Want to learn more?

Join CodeFriends Plus membership or enroll in a course to start your journey.