Re: GNOME development tools; A more United future?

[Rodrigo Moya <rodrigo gnome-db org>]

On Mon, 2001-09-03 at 12:21, David T. Bath wrote:
> On Mon, 3 Sep 2001 19:46, Rodrigo Moya wrote:
> > On Mon, 2001-09-03 at 04:26, Andrew Hill wrote:
> 
> > > > > The problem is that I need backend information from the postgresql
> > > > > database like (GORY DETAILS SNIPPED)
> Bingo.  And that's gonna be a REAL pain when you get into the advanced
> object-relational stuff like Oracle, or Postgres with that cute little
> KDE program "koalas" (did anyone see that?)
> 
no, I haven't seen koalas. Have you got a URL?
> 
> > > Be a pain for someone to go though each db and find out how to get the
> > > information
> > > and add the support.
> 
> It depends whether you have the ANSI SQL info views or not.
> USER_TABLES, ALL_VIEWS and the like have been in the standard
> for years, but not universally implemented, and apart from the
> old KnowledgeMan, darn difficult to use with flat files or xBase
> which is needed by a generic rdbm access method.  Even then,
> KnowledgeMan required you to run a procedure to populate the
> tables, taking a list of files (tables) and/or directories
> as arguments.
> 
well, in gnome-db, we don't use SQL to access that information from
clients. That is, we've got a single function, to which you specify a
list of constraints that describe the set of information you want to get
from the database. For instance, to get all fields in table "table1":

GdaRecordset *recset;
GdaConnection *cnc;

...
recset = gda_connection_open_schema (cnc,
                                     GDA_Connection_GDCN_SCHEMA_COLS,
                                     GDA_Connection_OBJECT_NAME,
"table1",
                                     GDA_Connection_no_CONSTRAINT);

for each DBMS supported, the implementation of this function is
different. That is, some DBMS will just issue a SQL query, like
postgres, others may read a file, or whatever.

So, what I mean with this is that adding support for new information
about the DBMS objects to gnome-db is as easy as just adding new
constraints (GDA_Connection_GDCN_SCHEMA_WHATEVER), and implement that
schema for each DBMS supported. gnome-db clients will only have a simple
entry point (gda_connection_open_schema) to get all the information from
the DBMS.

cheers
-- 
Rodrigo Moya <rodrigo gnome-db org> - <rodrigo ximian com>
http://www.gnome-db.org/ - http://www.ximian.com/