Summary of SQL Join Syntax

 1. Cross Join
  * the result is Cartesian product or simply product
  * e.g., Movie ''CROSS JOIN'' StarsIn

 1. Theta Join
  * Product on some conditions
  * e.g., Movie ''JOIN'' StarsIn ''ON'' title = movieTitle AND year = movieYear
  * default is LEFT INNER JOIN

 1. Natural Join
  * the condition in theta join is just all pairs of attributes with same name
  * one of each pair of same name is projected out
  * e.g., MovieStar ''NATURAL JOIN'' MovieExec

 1. Outer Join
  * augment the result of a join by the dangling tuples, padded with null values
  * e.g., MovieStar ''NATURAL FULL OUTER JOIN'' MovieExec
  1. FULL OUTER JOIN
  1. LEFT OUTER JOIN
  1. RIGHT OUTER JOIN

 1. Semi Join
  * [http://www.dbspecialists.com/presentations/semijoins.ppt Speeding Up Queries with Semi-Joins and Anti-Joins]
  * [http://www.dbspecialists.com/presentations/semijoins.html Speeding Up Queries with Semi-Joins and Anti-Joins]

 1. References
  * [http://en.wikipedia.org/wiki/Join_(SQL)]