Hi Quinton,
Thank you very much for this explanation, it makes a lot more sense
now.
But I'm not completely dissuaded by this. The next AUTO_INCREMENT
key is stored in table metadata - where it can be read and written
to. So would it not be possible to hack the mysql driver to use
this value instead of using the one in the EO_PK_TABLE?
I am not familiar with how MySQL stores this, but this sounds quite
possible to me. The plugin simply needs to be able to return a new
primary key value. EOF does not care how it gets that value.
Chuck
On 04/10/2008, at 9:58 PM, Q wrote:
On 04/10/2008, at 5:31 PM, Richard Stephens wrote:
Unfortunately, most of the PHP stuff doesn't use any database
abstraction. Converting it to se a different database would be a
huge task.
I guess I just don't understand why WO has to store the next key
in a table, rather than in the table metadata where
AUTO_INCREMENT stores it.
The reason that WO just doesn't work well with AUTO_INC is because
it expects to be able to obtain an id for the EO BEFORE the insert
is executed so that it can resolve temporary id's and any foreign
keys in a transaction safe way. When you use AUTO_INC, you don't
know what the ID is actually going to be until after it has been
inserted. What you need in order to do this properly is a sequence,
which mysql lacks, but the behaviour can be emulated by using the
EO_PK_TABLE. You may be able to sort of resolve the issue of
EO_PK_TABLE being out of date by using a trigger to update the
EO_PK_TABLE on INSERT, or better yet use a trigger to use the
EO_PK_TABLE to generate the ID value instead of allowing mysql to
AUTO_INC the ID field, but I have never actually tried to do that.
Alternatively, in my case, even using SELECT MAX(pk) might be an
option, as the WO code doesn't actually create new entities very
often.
Is there source available for the mysql driver? I wouldn't mind
having a look see if I can adapt it
Regards,
Richard Stephens
Ph: 07 3136 3426
Mob: 0410 111 570
Email: [EMAIL PROTECTED]
On 04/10/2008, at 4:10 PM, Guido Neitzer wrote:
On 03.10.2008, at 23:32, Richard Stephens wrote:
Is there any way to get round having to use EO_PK_TABLE for
mysql and to allow WO to use auto_increment instead? I'm
writing a WO app that has to share a mysql database with a
number of PHP apps, so the data that ends up in EO_PK_TABLE
can't be trusted.
We had a hard time doing that (working around issues in MySQL)
and ended up converting the projects to either FrontBase or
PostgreSQL and within a day all pain was gone ...
The problem is, that WO just doesn't work the way, auto-increment
works. And it's less pain to use another database than to deal
with all these problems in my opinion. If that is not an option,
just ignore me ...
cug
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Seeya...Q
Quinton Dolan - [EMAIL PROTECTED]
Gold Coast, QLD, Australia (GMT+10)
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Chuck Hill Senior Consultant / VP Development
Practical WebObjects - for developers who want to increase their
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