Why are joins denoted left, right, inner, outer

[AJR]

Hi

Can't seem to find an explanation for why joins are denoted as left/right or Inner/Outer. If I know why it would probably help me remember which is which.

Thanks

AJR

 

[jdraw]

see
http://www.w3schools.com/sql/sql_join.asp

 

[John Big Booty]

This article seems to have a pretty good explanation of the various joins. This article has a handy table to show you how the various joins operate and where to use them.

 

[AJR]

Thanks for the links. I'm on my way over now

AJR

 

[Pat Hartman]

It's a visual thing. Look at a Venn diagram that shows two overlapping circles. the place where the circles intersect is "inner", the left circle is what you get with a left join and the right circle is what you get with a right join.

http://en.wikipedia.org/wiki/Venn_diagram