To further enhance our SQL & problem-solving skills, my friend and colleague Vasileios Tsakalos (https://github.com/Tsaqeal) suggested https://www.sql-practice.com.
The sandbox environment utilises two different databases:
- hospitals.db
- northwind.db
The difficulty levels for both databases are the same:
- Easy
- Medium
- Hard
Numbers of exercises per database:
| Difficulty⬇️ / Database➡️ | hospital.db | northwind.db |
|---|---|---|
| Easy | 16 | 9 |
| Medium | 26 | 4 |
| Difficult | 10 | 2 |
- The platform is using SQLite. Hence, you might find that some of the functions do not work as expected.
- I am not entirely sure whether the exercises increase over time (with new ones being added), but I will update the existing repository, should new exercises are added.
- You can add questions (also providing their respective WORKING solutions) using the following form: https://www.sql-practice.com/question_form/
What you will find in the repository is our attempts to solve the puzzles in a way that works and makes sense (rationally). We do realise that there are alternatives (which, we will provide in some cases) or simpler ways and we welcome you to leave comments or code improvements.
The language and the syntax used was basic SQL (with some intermediate combinations) in a way that would work universally (as along the way, we have realised there are some compatibility issues with the use of certain functions in the online environment).
We would definitely appreciate your (constructive) feedback and further contribution.
Thank you.