A guide to writing correct and efficient SQL join logic

Do you work with databases? Do you use SQL as part of your work? If so, would you like to use SQL with greater proficiency?
Then this course is for you! In "Subtleties of Joins" we study different ways of using joins in database queries and their trade-offs.
Joins can be computationally expensive, so it's important to express them properly. Furthermore, a misstated query can yield a wrong result, Correct use of joins makes your SQL code more readable and understandable. This is especially important for lengthy and complex queries.
Specifically, this course covers the following
Join vs. Where. There are guidelines for placing logic in joins vs. where clauses.
Join filtering. Outer joins necessitate that some data filters be in joins rather than in where clauses.
Joins vs. Nested SQL. Queries with nested SQL can sometimes be restated to use joins instead.