Re: AW: AW: AW: [Objectbridge-developers] generating mapping files an d da taba ses

[Ivan T. <to...@cr...>]

On Fri, 2001-08-24 at 12:47, Mahler Thomas wrote:
> Hi again,
>=20
> > -----Urspr=FCngliche Nachricht-----
> > Von: Ivan Toshkov [mailto:to...@cr...]
> > Gesendet: Donnerstag, 23. August 2001 17:14
> > An: Mahler Thomas
> > Cc: 'Lasse Lindg=E5rd'; obj...@li...
> > Betreff: Re: AW: AW: [Objectbridge-developers] generating=20
> > mapping files
> > and da taba ses
> >=20
> >=20
> > On Thu, 2001-08-23 at 16:40, Mahler Thomas wrote:
> > > > Unfortunately, there isn't quite enough data in the=20
> > > > repository.xml file
> > > > to generate the correct SQL statements.  So far, I don't=20
> > know when to
> > > > generate 'NOT NULL' and the size of VARCHAR objects.
> > > >=20
> > > > So, perhaps we should add this data to the XML?
> > > >=20
> > >=20
> > > Yes I have been thinking in this direction too.
> >=20
> > Ok, I've added the following two attributes to jdbc_type:=20
> > 'not-null' and
> > 'size'.  The problem is that (even in the test repository) many tables
> > are described in several places each, which can lead to inconsitency.
> > So, what do you think of the following form?
> >=20
> > <MappingRepository>
> >   <JdbcConnectionDescriptor id=3D"default">
> >      ...
> >   </JdbcConnectionDescriptor>
> >   <JdbcConnectionDescriptor id=3D"other">
> >      ...
> >   </JdbcConnectionDescriptor>
> >   ...
>=20
> I like this idea to keep the JdbcConnectionDescriptors out of the
> ClassDescriptors!
>=20
> >   <TableDescriptor name=3D"table_name" id=3D"tableId"
> >                   [jdbc-ref=3D"other"]>
> >      <ColumnDescriptor name=3D"columnName" [primaryKey=3D"yes|no"]
> >                       [not-null=3D"yes|no"] .../>
> >   </TableDescriptor>
> >   ...
>=20
> it's also good to have tables separately described from classes, as sever=
al
> classes may be mapped to the same table!
> I think we need some more information for jdbc_type, as size works only f=
or
> CHAR(X) and VARCHAR(Y), but there are also things like DECIMAL(6,2) or
> NUMERIC(3,8) allowed in SQL !
>

Well, this may not be the best solution, but size=3D"3, 8" could do the
trick.

Of course, if there is more information needed, we should put it.

> Maybe it's also a good idea to have a switch [indexed=3D"yes|no"]. This w=
ould
> allow to generate indexes on certain columns that are used in where claus=
es.
>=20
Sure!