12.Translate Joins

Algebra	SQL
`r ⋈ θ s`	`r JOIN s ON θ`
`r ⋈ s`	`r NATURAL JOIN s`

instructor ⋈ teaches
π instructor.name, department.dept_name (instructor ⋈ instructor.salary > department.budget (σ building = 'Champlain' (department)))
Which attribute do instructor and course have in common?
How many tuples does instructor ⋈ course return? Work it out, then run it to check.

Something unclear, wrong or missing?

Databaselab-db · PostgreSQL in your browser 0:00

SELECT * FROM instructor JOIN teaches ON instructor.id = teaches.id;

Ctrl↵runs the query · select text to run part of it

Objective 1 of 40/4 done