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

[Mahler T. <tho...@it...>]

Hi again,

> -----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>
>   ...

I like this idea to keep the JdbcConnectionDescriptors out of the
ClassDescriptors!

>   <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>
>   ...

it's also good to have tables separately described from classes, as =
several
classes may be mapped to the same table!
I think we need some more information for jdbc_type, as size works only =
for
CHAR(X) and VARCHAR(Y), but there are also things like DECIMAL(6,2) or
NUMERIC(3,8) allowed in SQL !

Maybe it's also a good idea to have a switch [indexed=3D"yes|no"]. This =
would
allow to generate indexes on certain columns that are used in where =
clauses.



>   <ClassDescriptor [table-ref=3D"tableId"]>
>      ...
>      <FieldDescriptor [column-name=3D"columnName"]>
>         ...
>      </FieldDescriptor>
>   </ClassDescriptor>
> </MappingRepository>
>=20
>=20
>=20