In this exercise, you are challenged to write a query to solve a challenge that involves set operators.
- [Instructor] Your challenge for this chapter … is to show breeds that were never adopted. … It is not the animals that were not adopted. … It's the breeds that were not adopted. … And this may sound like a minor change … but trust me, it is not. … There is a fundamental logical difference … between these two questions. … Breed isn't an animals identifier. … We have more than one animal of the same breed. … Moreover, none breed animals have null for breed, … which throws another monkey wrench into the query. … A few tips. We have none breed dogs and none breed cats. … So remember, you must consider species as well. … Breed alone is not enough. … I'll give you the answer for the sample data. … The only breed that was not adopted is a Turkish Angora cat. … This is going to help you a lot identify any wrong solutions. … Before you attempt to use set operators, … I ask that you try some of the techniques … we just used to find animals that were never adopted … and see whether or not these techniques work. …
This course was created by Ami Levin. We are pleased to offer this training in our library.