Visual Representation of SQL Joins – CodeProject

I thought I posted a reference to this a long time ago, but didn’t.

It’s one of the things I show when explaining joins to people. Sometimes I need it myself too (:

The article explains these in greater detail:

• INNER JOIN
• LEFT JOIN
• RIGHT JOIN
• OUTER JOIN
• LEFT JOIN EXCLUDING INNER JOIN
• RIGHT JOIN EXCLUDING INNER JOIN
• OUTER JOIN EXCLUDING INNER JOIN

Note:

• the opposite of INNER JOIN is not OUTER JOIN. It’s OUTERJOIN EXCLUDING INNER JOIN
• the opposite of OUTER JOIN is empty set.

But the diagram is usually speaks for itself.

–jeroen

Source: Visual Representation of SQL Joins – CodeProject