csnotes/cst363/lec/lec6.md

lec6

Lab activity

This lecture features a lab activity in the lab/ directory named: courses-ddl.sql with instructions in simple-joins-lab.pdf.

• Note: Just make sure to read int courses-ddl.sql first then courses-small.sql second otherwise there will be random errors.(I'm not taking responsibility for that garbage so don't flame me)

Natural Joins

Natural Joins: allows us to join tables while getting rid of duplicate columns automatically.

Form:

select columns_[...] from tableLeft natural join tableRight

While ther is no need to write extra where statements there is also the issue where there may be accidental matches since attributes are dropped.