[Zope] "Automatic" creation of searchable documents from Oracle DB tables

[Kapil Thangavelu]

Chris Beaumont wrote:
> 
>    Part 1.1Type: Plain Text (text/plain)
Hi Kapil, (and fellow Zopatistas)

Well, it's been difficult, but I finally feel as if I'm on the verge 
or understanding this a bit better..

Thank you for taking the time to explain this.
I would think, it's a fairly simple thing I'm trying to do. Hehehe.. 
Famous last words.. huh?

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#Kapil
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i say it all the time:)

before i go on i should probably say that i'm not sure about the
benefits of using zclass  presentation of sql data in this case. you're
trying to enforce a one-to-one object to event ratio but to what
benefit, the only one thats readily apparent to me are the urls.
The functionality for display could easily be done with a few pages and
some sql methods in instead.

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So, anyway, I've been staying up till 2 am almost every night trying 
to absorb as much of this as I can, but I have an (extensive) web 
development, but not a programmer's background, and I'm very much a 
Zope newbie, so I need to ask you some more questions.. I hope you 
don't mind..

You can get a feel for what I am talking about by looking at any of 
the programs or workshops on the website I manage, www.msri.org.
Currently, I'm doing this site by rendering these fields of info 
through templates into static pages in Frontier, but I'd like to 
transition to Zope.
(Its the old webmaster's dream of the "self-maintaining site"  *LOL*)

So here's where I'm at so far.. I have built an Oracle 7 database to 
hold the event info.. Everything fine there, everything works.. now 
for the fun stuff..

I have several tables in this "event" section of the database, 
programs, workshops and talks. (there actually is one other table for 
other kinds of events) Each kind of event is treated somewhat 
differently in the schema. It's a very simple setup with nothing 
exotic going on..  Logically, a given workshop is usually tied to a 
program..and a given talk is usually tied to a parent workshop.


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I have been successful in setting up the basic web-database 
interaction. I made the basic insert and query forms that are 
described in the ZSQL Users Guide, and  as I said in my previous 
posting my next goal is to be able to create separate documents from 
the data in the individual records that are inserted into the 
tables.. I'd like to be able to search them along with the other Zope 
documents on the site, at once, (using a ZCatalog..hopefully)


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ZCatalog searches of the RDBMS are generally not possible or
recommended(size concerns). It might be possible catalog the objects
based on an sql method within the zclass that takes no args. Search the
mailing lists for more on this. doing this would probably require doing
this as a base python product with a zclass inheriting from it, so you
can create the sql method with the proper syntax without an arg.

Another possibility since you're using oracle is intermedia/context
indexing, although i'm not sure if it exists in oracle 7, and its a pain
to setup (see technet.oracle.com and www.arsdigita.com/bboard for help).

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I also need to be able to quickly build several different kinds of 
automatically-maintained lists from SQL queries that home in on 
various subsets of the event data. (Ultimately, this system will be 
expanded to handle "people" data, which will involve some very large 
lists of people spanning over 20 years, so this system needs to have 
decent performance with large datasets...But, even then, the result 
set of a given query will always be quite small..)

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if you're trying to change your zope object heirarchy based on these
lists you should just do the whole thing in sql which is designed for
relations. IMO object dbs are designed for interaction.


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Starting with (on the insert record side) I have an SQL Method for 
each event type that describes the permissable arguments, and the 
code describing the multi-field  insert.

(I have a sequence and trigger already working on the database side 
of things that implements a unique ID -the primary key- for each new 
program, so the ID is not one of the arguments passed through the 
ZSQL Method..should I change this? - I could do this some other way..)

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keep your sequence. in your insert method do an sql delimter and select
the id of the inserted record, assign this as either a property or the
id of the zclass. the property might be better if you want to have a url
which has some semantic sense to it.

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I also have another SQL method for each type of event that does a 
select * from <event_type> so that I can implement pulldowns in the 
select form for the child workshops of a program. (This is really 
nice and is one of the reasons I think Zope will be great for 
building a highly useable web interface to this database,  widgets 
like this make it easy to keep referential integrity..)

Then, one (in the case of the event types without possible "parents") 
or both of the SQL Methods are called in an DTML Document input form. 
When the form is submitted a DTML Method is triggered, which right 
now only shows an acknowledging thank you to the person who submits 
the information.

So, if I understand you correctly, **I should then use that action to 
create a class that is tied to the primary key of the database table. 
Is there an example somewhere of this RDBMS table-keyed "automatic" 
creation of ZClasses or DTML documents?*

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when the form is submitted to the a dtml method. that method should call
the sql method get the result back from it which is the id of the record
and create the zclass and change its properties to reflect the proper
zclass.

there are how tos on programmatic insertion of ZClasses, and ZClass
properties

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  I think ZClasses would be preferable because there are several kinds 
of event pages I'd like to generate for each kind of event.. (for 
example, sometimes we have short-term housing information we want to 
show, and a few weeks before a given event, as more information 
becomes available, I'd like to be able to have it added .. For 
example, as an event time nears, I almost always have to put up 
schedules of the talks in a given workshop..)


Anyway, if you have the time and can think of any handy pointers to 
documentation or relevant examples, Id appreciate it.. But even if 
not, you already have given me a good start..  It shouldn't be very 
hard, but even though I've been putting in a lot of time searching, 
finding information has been difficult for me.. The closest I could 
find to what I want to do is the (very)  few snippets of information 
available about "pluggable brains". But there isn't even a HOWTO on 
this, a question that should be a common question..  If anyone has 
any pointers for a beginner. I'd be really grateful..



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with regards to searching for info. the google search on zope.org is the
probably the fastest mechanism to finding the info you want (accessible
from the search link on the top of the page)

unless you certain of some benefits of doing this with ZClasses wrapping
your db records i would suggest reading up on some sql and doing the
site with sql.

Good luck

Kapil
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