Comments on: How to do an OUTER JOIN in Query of Queries

By: David Beale

David Beale — Thu, 08 Jul 2010 10:37:08 +0000

@Nikos

No its not in CF9

You should just be able to add extra conditions to the main WHERE expression.

By: Nikos

Nikos — Mon, 05 Jul 2010 14:06:17 +0000

How do you do this if you have 2 join condions?

cond1 & cont2

cheers

By: Nikos

Nikos — Mon, 05 Jul 2010 13:53:54 +0000

is this still not supported in cf9?

By: Garrett

Garrett — Fri, 31 Jul 2009 18:10:21 +0000

I’ve got this set up but the output returns duplicate rows of the list in NOT IN statement rows in addition to the originally selected rows – just without the additional data

Any thoughts?

SELECT *
FROM joinclientquery, GetLossData
WHERE GetLossData.client_number1 = joinclientquery.cclientid

UNION

SELECT joinclientquery.*, joinQuery.*
FROM joinclientquery, joinQuery
WHERE joinclientquery.cclientid NOT IN (#quotedValueList(GetLossData.client_number1)#)
order by cclientname

sample output

100386 457,466 0 0
100386 100386 1 1 0 457,466 0 0

By: David

David — Tue, 26 May 2009 17:43:19 +0000

Also, as a side note…. if the join field is a string, you’ll need to change the “ValueList” to “QuotedValueList”

But thanks for this great code. I just ran it on Portable Blue Dragon/Jetty, and it works fine.

By: Thomas Gorgolione

Thomas Gorgolione — Tue, 03 Feb 2009 20:48:23 +0000

@Matt – With UNION you need the same amount of columns in the second query result as the first, hence the creation of a “null row” in the first few lines and a join with that row to the second query. I was kinda wondering that myself before I looked at UNION here: http://www.w3schools.com/sql/sql_union.asp

By: Matt

Matt — Mon, 02 Feb 2009 13:35:51 +0000

I dont get it.

I am just going through the logic but dont understand why do this:

SELECT *
FROM QueryB
WHERE QueryB.ID = -1

When it return zero rows as no ID matches -1

and then just add 1 row to it.
Can someone enlighten me or am i missing something here…

By: David

David — Sat, 02 Aug 2008 14:58:14 +0000

@Richard

Yes that’s a typo, it should be SELECT QueryA.*, joinQuery.* I’ve updated the post.

The CROSS JOIN in the second query is used to include the empty columns from the joinQuery to the filtered results from QueryA. This is done to give the results set of a LEFT OUTER JOIN.

I should also state that this technique assumes that the joining columns (.ID) can never have a value of -1. e.g. They are auto-numbers of a primary key.

By: richard white

richard white — Sun, 29 Jun 2008 22:32:46 +0000

hi,

the code above is not the finished product right? i am trying to replicate it but on the line:

SELECT QueryA.*, joinQuery

joinquery is not a collumn therefore it is producing an error.

Also, you don’t specify a join condition in the second query of your UNION statement, which means that it’ll return a Cartesian product

thanks

By: David

David — Thu, 19 Jul 2007 20:56:44 +0000

@ Pat

Thanks for spotting that.

I have updated the post to correct the issue. It makes it a bit more complicated, but at least it works