sqool is a project dedicated to tasks and algorithms of structured data processing. The name "sqool" was chosen as a combination of the words school and SQL. SQL (structured query language) is by far the most common language for data processing, so we use it to write our tasks.
We like interesting tasks and people who enjoy solving them!
We are convinced that logic is more important than politics, and aesthetics is present even in the algorithms.
Yes, today sqool gives you the opportunity to practice SQL for free. Perhaps later we will add additional premium features, but the basic functionality will always remain free.
We are happy to discuss ideas for new tasks!
Please use this form to submit your proposal.
We will get back to you, promised! In case of publication your authorship will be indicated in the task attributes.
For each task in our library there is a saved query, which we consider to be the right solution.
After the user submits his solution, the user's and our query are executed simultaneously on the database. The results of both queries are then compared (the order of lines is ignored).
User's query is considered correct if both results are the same.
When checking a user's solution, the query is executed and compared on two different databases: open and hidden.
The result from the open database is displayed to the user. Hidden database serves as a second level of the validation and is never shown to the user.
Thus, the use of the hidden database allows us to be sure that the user's solution works not only on one specific example, but is really generic.