Learning the theory behind databases, syntax and semantics of SQL is very important. If, however, we want to truly master databases, we need to learn how to apply the theory in the real world. There is no better way to learn that than by solving exercises!
To help you with this, we have prepared for you the Database Tester. It contains tons of exercises ready for you to solve. We have carefully crafted them in a way that each exercise helps master a particular database competence.
Each exercise contains not only a description, but also a database full of test data. You can inspect the database structure and the data for yourself. It will help you better grasp the exercises.
You can even run your SQL commands against the database to see what the effects of your commands are. If your solution does not work for certain rows, you can inspect them and the related rows. This will help you find out the cause of the problem more quickly.
You know what? The tester checks each solution you submit and instantly tells you whether you have it right.
No more uncertainty as to whether or not your solutions are correct. Build up your confidence, and proceed to the next exercise once you know for sure that you have correctly solved the current one.
The tester not only tells you whether your solution is correct or incorrect, it also gives you a comprehensive feedback. It shows you which rows you are missing in your result sets, which are unexpected, which tables and columns you have forgotten to create, etc.
All this information will help you find out why your solutions are incorrect more easily. You will save time trying to figure out what is wrong with your solution and will have more time to dive into the following exercises.
There is no need to save your solutions on your computer. The tester saves them for you and you can easily access them whenever you need. Whether the solutions are correct or not. You can always pick them up and continue your work.
The tester also tracks your progress - which exercises you have solved correctly, which are ongoing, and which you haven't started yet. This way you always know where you are on your journey, and it keeps you motivated to see the percentage of unfinished work dropping.
We provide our correct solutions to each exercise for you to see so you can compare your solution with ours to see which is better. Either ours is better and you can learn even more by studying it, or yours is better and you can feel proud for beating us!