Donna,
>Try looking at the information_schema.KEY_COLUMN_USAGE table (where
>referenced_table_schema is not null). It will show you the FK
>relationships. You could then create a tree that you could use to find the
>hierarchy. For that, I suggest looking at
>http://www.artfulsoftware.com/infotree
Try looking at the information_schema.KEY_COLUMN_USAGE table (where
referenced_table_schema is not null). It will show you the FK
relationships. You could then create a tree that you could use to find the
hierarchy. For that, I suggest looking at
http://www.artfulsoftware.com/infotree/mysqlquer
Sounds like you want to walk tables in order of their fk dependencies
- a topological ordering. You might want to take a look at SQLAlchemy
which has some methods to do just this in sqlalchemy.sql.util:
def sort_tables(tables, reverse=False):
"""sort a collection of Table objects in order of
Andy Shellam wrote:
Am I missing something here? (It is late after a long day, I admit!)
Only something I forgot to mention.
All the foreign keys are set up as ON DELETE RESTRICT, meaning MySQL's
response to a foreign key violation is to spit out an error message to the
effect of "I'm sorry
Hi Philip,
Am I missing something here? (It is late after a long day, I admit!)
In the example case you've given, if the foreign key in Parts is set to
ON DELETE CASCADE, and you delete a row from Manufacturer, MySQL will
first delete the associated records in Parts before deleting the row
f
Hi,
First of all, I apologise in advance for any mind-altering, or
headache-inducing effects this question may have. I've spent the past two days
trying to figure it out, and all I've got to show for it is a mostly-working
recursive depth-first-search routine and an empty packet of painkiller
On Tue, Feb 3, 2009 at 1:54 PM, Jerry Schwartz
wrote:
> From: Martin Gainty [mailto:mgai...@hotmail.com]
> Sent: Tuesday, February 03, 2009 1:03 PM
> To: Jerry Schwartz; mysql@lists.mysql.com
> Subject: RE: WHERE vs. ON
> ON condition uses the same columnname from both source and target tables
>
>
From: Martin Gainty [mailto:mgai...@hotmail.com]
Sent: Tuesday, February 03, 2009 1:03 PM
To: Jerry Schwartz; mysql@lists.mysql.com
Subject: RE: WHERE vs. ON
ON condition uses the same columnname from both source and target tables
whereas any column expressions can go in the WHERE claus
On Tue, Feb 3, 2009 at 12:24 PM, Jerry Schwartz
wrote:
> Somebody, I think it was somebody from MySQL, said that you should never put
> anything into a WHERE clause that could be put into the ON clause of a JOIN.
> My guess is that this helps with the optimization, but it seems
> counter-intuitive
ON condition uses the same columnname from both source and target tables
whereas any column expressions can go in the WHERE clause...
Martin
__
Disclaimer and confidentiality note
Everything in this e-mail and any attachments relates to the official
Somebody, I think it was somebody from MySQL, said that you should never put
anything into a WHERE clause that could be put into the ON clause of a JOIN.
My guess is that this helps with the optimization, but it seems
counter-intuitive to me. I've never followed that advice, but I'm starting
to exp
Hi!
> "Konstantin" == Konstantin Osipov writes:
Konstantin> * Michael Widenius [09/01/30 14:53]:
>> Its more important that we don't break things for current users than
>> try to be concerned about possible wrong usage that no one seams to do
>> or find important enough to complain about.
Hi all,
Below are the two examples. In the example 2 its giving 'Reading table
information.' where as in the example 1 its not giving.
I am not able to find out why it is. Example 2 server is configured by me
where as example 1 server is configured by some body else.
Example 1
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