Different types of JOINs
- INNER JOIN: Returns all rows when there is at least one match in BOTH tables
- LEFT JOIN: Return all rows from the left table, and the matched rows from the right table
- RIGHT JOIN: Return all rows from the right table, and the matched rows from the left table
- FULL JOIN: Return all rows when there is a match in ONE of the tables
- SELF JOIN: is used to join a table to itself as if the table were two tables, temporarily renaming at least one table in the SQL statement.
- CARTESIAN JOIN: returns the Cartesian product of the sets of records from the two or more joined tables .
For more about sql join
http://www.w3schools.com/sql/sql_join_inner.asp
http://www.sql-join.com/sql-join-types
https://www.tutorialspoint.com/sql/sql-inner-joins.htm