Re: About Database Vender Independent for WebObjects.
Re: About Database Vender Independent for WebObjects.
- Subject: Re: About Database Vender Independent for WebObjects.
- From: Jean-François Veillette <email@hidden>
- Date: Mon, 31 Jan 2005 09:27:05 -0500
In order to reimplement yourself accessor method, and have full control
over that object, you need that entity to be represented as a custom
class (not use the EOGenericRecord class). To ease working with custom
class, it's recommended to use the generation gap pattern, use
'EOGenerator' (look on the net for it), it's a tool that will automate
the use of that pattern.
Be carefull in reimplementing common accessor methods, take care not
interfering with EOF ... you may end up fighting against EOF if your
not doing it the EOF way.
If your thinking to reimplement accessor methods just to reimplement
the sql needed to do the fetch, then this is not 'EOF friendly' if that
same attribute is told to be managed by eof.
You usually do not reimplement accessor methods but add more methods
instead. Add more method to an object so that it's no longer just a
value holder, it become a full business logic object.
Both "Struct" and "JGeometry" are in a sdoapi.jar provided by
Oracle, meaning they are proprietary. It also has to use
PreparedStatement other than just normal resultset or one simple SQL
script. This is what make me really doubt it that EOF can handle it
all by itself. You'll have to be able to actually modify the generated
Enterprise Object file to do this.
To use JGeometry and any other custom object structure, look at custom
data type.
You would have to tell eof how to transform the binary received from
the DB to an object on the java side.
file:///Developer/Documentation/WebObjects/UsingEOModeler/
4WorkingWithAttributes/index.html
look around "custom value class for an attribute" and related topics.
I have never used custom value class for such use, I have used it in a
more conservative way and it worked well. If I was facing your
challenge, this is where I would start looking.
If custom value class can't do the job for your needs, then I guess you
would need to look at the access layer of eof, ultimately look at the
jdbc (and plugin) layer itself. I hope you do not have to go there.
- jfv
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