Frustrated Join?

[Guest]

I've seen this description of a join used several times in recent posts.
Anyone care to give either a definition or references?

Thanks.

 

[Rick Brandt]

I've seen this description of a join used several times in recent
posts. Anyone care to give either a definition or references?

It's used when you want to see all the records in one table that do not have
matches in another table.

SELECT *
FROM TableA Left Outer Join TableB
On TableA.ID = TableB.ID
WHERE TableB.ID Is Null

The Left Outer Join would normally indicate "give me all records from
TableA" but the WHERE clause "frustrates" that by limiting the results to
those rows where no matching record exists in TableB.

 

[Guest]

Thanks for the response, Rick.

Any references? I tried Googling for 'Frustrated Join' and 'Frustrated Outer
Join' and all I came up with were requests for people who were frustrated by
something or other to join some advocacy group <g>. Not the same thing.

And, of course, references to some of Allen Browne's post to these news
groups, which were the source of my question.

Once again, thanks!

 

[Rick Brandt]

Thanks for the response, Rick.

Any references? I tried Googling for 'Frustrated Join' and
'Frustrated Outer Join' and all I came up with were requests for
people who were frustrated by something or other to join some
advocacy group <g>. Not the same thing.

And, of course, references to some of Allen Browne's post to these
news groups, which were the source of my question.

I believe it is a term that Allen coined. It is not technically called
anything but an Outer Join.