Learn Standard SQL Functions | Interactive Course | Vertabelo Academy

Deals Of The Week - hours only!Up to 80% off on all courses and bundles.-Close

16/37 COUNT – additional exercise 2

1. Introduction

2. Table translator

3. Table project

4. Count all rows

5. COUNT with column

6. COUNT(*) vs. COUNT(column) – practice

7. COUNT with expression

8. COUNT DISTINCT

9. COUNT DISTINCT with expression

10. COUNT and GROUP BY

11. COUNT and GROUP BY – additional practice

12. COUNT DISTINCT and GROUP BY

13. COUNT DISTINCT with expression and GROUP BY

14. Common mistake: COUNT(*) and LEFT JOIN

15. COUNT – additional exercise 1

16. COUNT – additional exercise 2

17. Function AVG

18. AVG and GROUP BY

19. AVG and NULLs

20. AVG and NULLs only

21. AVG with COALESCE

22. COALESCE with AVG

23. AVG and DISTINCT

24. ROUND and AVG

25. AVG – additional exercise

26. Function SUM

27. SUM with NULLs only

28. SUM and COALESCE

29. SUM and DISTINCT

30. MAX and MIN

31. SUM, MAX and MIN – exercise

37. Congratulations

Okay. One more COUNT exercise, this time with some date functions.

For each language combination (e.g. EN to ES, ES to EN, DE to PL etc.) show lang_from, lang_to and two more columns:

the number of projects completed in this combination (as projects_no).
the number of translators that have completed at least one project in that language combination (as translators_no).

All completed projects are present in the project table.

Use COUNT twice. Remember that translators may have completed more than one project, so you'll need DISTINCT.

Our website uses cookies. By using this website, you agree to their use in accordance with the browser settings.You can modify your browser settings on your own. For more information see our Privacy Policy.