Introduction
What is a Join?
SQL Join is a concept of joining two or more tables. In special case, a table can be joined to itself called self-join.
How to Join more than 2 tables at one time?
What are different types of Joins?
SQL (standard) defines 4 types of Joins + 1 special case.
1. Inner (Simple Join)
2. Outer
3. Left (Outer)
4. Right (Outer)
5. Self Join
What is difference between Inner & Outer Join?
Answer
What is Anti Join?
What is Semi Join?
What is Equi Join?
Equi Join is just a name given to Inner Join when the "equal" comparison is done. In case the comparison is different than equal (e.g. <), it is not a Equi join. This term is of importance because the algorithm used for Equi are different from non-Equi once (e.g. Hash Join may not be used for non-Equi Join).