Re: querying against multiple SE DBs
>From: "Billy Wheeler" <billy@west.co.za>
>Date: Tue, 19 Nov 1996 18:22:31 +0200
>Subject: Re: querying against multiple SE DBs
>
>On 19 Nov 96 at 8:08, Jonathan Leffler wrote:
>
>> You can't do that with SE -- OnLine yes, SE no.
>
>Hell, I'm sure I've sone queries like
>SELECT *
>FROM //machine1:tableA
>INTO TEMP fred;>
>SELECT *
>FROM tableB, fred
>WHERE fred.a = tableB.a...
Hi,
I've not tried this for maybe 5 years, so I may be wrong.
Additionally, there have on occasion been loopholes in the behaviour of
temp tables with SE which meant that you could create a temp table T with
database A open, switch to database B, and still access T. On other
occasions, I believe, this has been fixed so that it can't happen, with
some uproar from customers as a result so that the fix may have been rolled
back out in a later release. Effectively, SE temp tables may not be tied
to any particular database, but also, depending on which version of SE you
have, the facility may or may not be available. I think it only works with
temporary tables as you show -- you cannot join two tables from two
different databases in a single select using:
SELECT *
FROM //machine1:tableA A, //machine2:tableB B
WHERE A.SomeColumn = B.SomeOtherColumn;
Of course, in OnLine (with I-Star if you're using a pre-6.00 version and
the databases are under the control of different OnLine servers), you can
do this, though you'd normally use the notation:
SELECT *
FROM dbase1@machine1:tableA A, dbase2@machine2:tableB B
WHERE A.SomeColumn = B.SomeOtherColumn;
Yours,
Jonathan Leffler (johnl@informix.com) #include <disclaimer.h>