Make your own free website on Tripod.com

InstantDB Project
About InstantDB
Project Mail Lists
Short History
Reporting Bugs
Screen Shots
3rd Party Examples
FAQs

Software
Downloads
Documentation
CVS Repositories
Roadmap
License

About Enhydra.org
Who We Are
News, Articles & Events
Getting Involved
Contact Us

Community
Demos
Contributions
Resources
Case Studies
On The Edge! -NEW-
Commercial Vendors


[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: InstantDB: How to join three or more tables?


Dirk

You can do three way joins in the WHERE clause with InstantDB, but
unfortunately, joins in the FROM clause are limited to only two tables. This
is mainly because I had assumed that the FROM clause would mainly be used
for OUTER joins, and InstantDB currently limits outer joins to just two
tables.

It's *supposed* to generated a slightly friendlier message than "Table not
found: null" to make this clear. I'll have a look at why it doesn't.

Regards

Pete

--

Peter Hearty                         peter.hearty@lutris.com
Lutris Technologies (UK)        http://www.lutris.com
----- Original Message -----
From: "Dirk Jesko" <jesko@iti.CS.Uni-Magdeburg.De>
To: <instantDB@enhydra.org>
Sent: Monday, October 16, 2000 9:13 AM
Subject: InstantDB: How to join three or more tables?


> Hello,
>
> InstantDBs SQL-Syntax allows joins with more than two tables, but
> executing a Query like:
>
> SELECT * FROM (t1 inner join t2 on t1.id=t2.t1id) inner join t3 on
> t2.id=t3.t2id
>
> results in the following SQL-Exception:
>
> java.sql.SQLException: Table not found: null
>
> I tried some other versions, e.g. with alias names for the tables,
> setting the  parenthesis differently, but it does not help.
> Querying the tables without using JOIN, like in:
>
> SELECT * FROM t1, t2, t3 WHERE t1.id=t2.t1id AND t2.id=t3.t2.id
>
> works fine.
>
> What is wrong with the query using the JOIN-Statement?
>
> Thanks,
> Dirk
> --------------------------------------------------------------------------
---
> To unsubscribe from this mailing list, send email to majordomo@enhydra.org
> with the text "unsubscribe instantdb" in the body of the email.
> If you have other questions regarding this mailing list, send email to
> the list admin at owner-instantdb@enhydra.org.
>

-----------------------------------------------------------------------------
To unsubscribe from this mailing list, send email to majordomo@enhydra.org
with the text "unsubscribe instantdb" in the body of the email.
If you have other questions regarding this mailing list, send email to
the list admin at owner-instantdb@enhydra.org.