SQL Joins versusTeoria dos Conjuntos/Set Theory

Achei isso na internet e achei bem legal, simples e explicativo:
I found this on the internet and I thought it pretty cool, simple and explanatory:

Visualizando esses conjuntos, lembrando das aulas de Matemática e aplicando nos comandos SQL, não tem como errar! Boa sorte!
Viewing these sets, remembering mathematics classes and applying in SQL commands, cannot go wrong! Good luck!

Adeus e té+!
Bye. See ya!

Leandro M:-D>
23jul2012/23ago2013
"Todos veem o que você parece ser. Mas poucos sabem o que você realmente é." 
(Nicolau Maquiavel, o Príncipe)
"Everyone sees what you appear to be, few experience what you really are." 
(Niccolò Machiavelli, The Prince)

np - Paradise Lost - How Soon Is Now (The Smiths cover)

'SELECT * FROM TableA A LEFT JOIN TableB ON A.Key = B.Key
'SELECT * FROM TableA A RIGHT JOIN TableB ON A.Key = B.Key
'SELECT * FROM TableA A INNER JOIN TableB ON A.Key = B.Key 
'SELECT * FROM TableA A LEF JOIN TableB ON A.Key = B.Key WHERE B.Key IS NULL
'SELECT * FROM TableA A RIGHT JOIN Table B ON A.Key = B.Key WHERE A.Key IS NULL
'SELECT * FROM Table A A FULL OUTER JOIN TableB ON A.Key = B.Key 
'SELECT * FROM TableA A FULL OUTER JOIN TableB ON A.Key = B.Key WHERE A.Key IS NULL OR B.Key IS NULL