4.8. Summary

After reading this chapter, you should have an appreciation of the concept of the join, a concept very fundamental to understanding relational databases. We have illustrated, with examples, the regular JOIN, CROSS JOIN and the Cartesian product, equi-joins and non-equi-joins, the self join, LEFT OUTER JOIN, RIGHT OUTER JOIN, and FULL OUTER JOIN. We have also discussed how multiple tables can be joined using a nested join.