Re: Cocoa/EOF for non-enterprise apps Re: proof of cocoa
Re: Cocoa/EOF for non-enterprise apps Re: proof of cocoa
- Subject: Re: Cocoa/EOF for non-enterprise apps Re: proof of cocoa
- From: James Duncan Davidson <email@hidden>
- Date: Wed, 20 Jun 2001 12:00:21 -0700
On Friday, June 15, 2001, at 10:44 AM, Deirdre Saoirse Moen wrote:
And, as far as the database adapter issue goes, WRITE THE DATABASE
ADAPTERS FOR ObjC TO TALK JDBC. I said that before and you missed it,
thus the caps. It's just a protocol.
JDBC is *not* a protocol. At least not in the way that protocol is
defined everywhere else outside of ObjC :). It's an abstract interface
that database vendors provide implementations for. Each db vendor uses
their own protocol (sometimes wire, sometimes shared memory, sometimes
other -- depends on configuration and database vendor) to access their
database behind their JDBC driver implementation.
JDBC defines only the API, and not anything behind that. It did so quite
consciously so that each driver can use the strategy that best suits its
configuration and database quirks. Oracle uses their own protocol to
communicate with remote databases, others do the same. In many cases
this support is written in a language other than Java -- especially when
using schemes possible on the same machine (shared mem, pipes, doors,
whatever) -- you have to use JNI. Some use all Java on the driver side
and "speak" the proprietary protocol back to the database.
But even when you have a pure Java driver "speaking" the protocol, it's
still not specified -- it's usually proprietary to the db manufacturer.
In order to use any JDBC driver from an ObjC program, you are going to
have to jump the bridge so that you can call methods on the JDBC driver
provided by the database vendor.
Now, it isn't beyond the realm of possibility that an ObjC/EOF
implementation couldn't always use the bridge to access the Java based
JDBC drivers, but that's a far different thing than saying that the db
adapters just need to talk JDBC.
James Duncan Davidson
email@hidden