Dan,
I love this. I'm going to implement it this way.
Thanks,
-dain
> -----Original Message-----
> From: Dan OConnor [mailto:[EMAIL PROTECTED]]
> Sent: Monday, August 27, 2001 9:59 AM
> To: [EMAIL PROTECTED]
> Subject: Re: [JBoss-dev] SQL reserved words
>
>
> Hi Dain,
>
> Why not use a sequential alias with no meaning, and let the user
> specify a single global unique postfix in a config file if necessary
> (e.g. "t1", "t2", "t3", and the user can make this "t1_myunique",
> "t2_myunique", "t3_myunique")?
>
> -Dan
>
> On 26 Aug 01, at 23:50, Dain Sundstrom wrote:
>
> > David,
> >
> > I need create aliases when a table is used more then once
> in a EJB-QL query.
> > It is really easy to get into this situation, so aliases
> are always used. I
> > could let the db compain, but then the user would have no
> recourse, as
> > EJB-QL is currently the only way to define an ejbSelect. I
> looked at the
> > getSQLKeywords function, and I think it is a good start.
> We will still need
> > the ability to specify additional keywords, because the
> drivers sometimes
> > lie.
> >
> > Does this explain the issue more? This is only for EJB-QL,
> but could be
> > expanded to other auto-generation code like table and column name
> > generation.
> >
> > I have been thinking that this code should be moved back
> into the jdbc
> > connector object... but that is for another day.
> >
> > -dain
> >
> > ----- Original Message -----
> > From: "David Jencks" <[EMAIL PROTECTED]>
> > To: <[EMAIL PROTECTED]>
> > Sent: Sunday, August 26, 2001 11:20 PM
> > Subject: Re: [JBoss-dev] SQL reserved words
> >
> >
> > > Probably I don't understand all the issues here,
> > >
> > >
> > > Why not just use the fully qualified column name
> relation_name.column_name
> > > always and dispense with aliases? You can't use a
> reserved word for a
> > > relation_name anyway, so you don't really need to worry
> about keeping
> > track
> > > of them... the db will complain.
> > >
> > > If you do want to keep track of reserved words, there is
> a database
> > > metadata method getSQLKeywords that might be helpful.
> > >
> > > david jencks
> > >
> > > On 2001.08.26 17:52:35 -0400 Dain Sundstrom wrote:
> > > > Hi all,
> > > >
> > > > I have been thinking over the issue of generation of
> table aliases in
> > > > EJB-QL
> > > > queries, and have run into some problems. What I want
> to do is prevent
> > > > the
> > > > EQL-QL assembler from generating table aliases that
> have been already
> > > > used,
> > > > that are reserved words, or are a db object name (i.e.,
> a table, view,
> > or
> > > > other name). I can handle the first to easily, but I
> can't think of a
> > > > way
> > > > to prevent collision with db objects.
> > > >
> > > > We could just tell users that they can prevent the code
> from generating
> > > > an
> > > > alias that is the name of a db object by adding the
> name to a reserved
> > > > word
> > > > list in the config file. I think this is reasonable as
> long as it is
> > > > rare.
> > > >
> > > > Then there is the issue of generating a database alias
> that it the same
> > > > as
> > > > an auto generated table name. This can happen because
> there is no
> > > > central
> > > > repository for the reserved word list. Let me explain
> the last claim a
> > > > little more. I am proposing adding a reserved word list to the
> > > > type-mapping
> > > > section section of the config file. The type mapping
> is selectable on a
> > > > per
> > > > bean level (newer feature). This means that each bean
> effectively has
> > > > it's
> > > > own datasource mapping information, and no central repository.
> > > >
> > > > Again, I think the only way around this is to have the
> user hand assign
> > > > the
> > > > table name and if collision persists add the table name
> to the reserved
> > > > list.
> > > >
> > > > I just don't like the idea of forcing users to do a lot of hand
> > > > configuration of the data mapping. I think the system
> should basically
> > > > work
> > > > without any jboss specific configuration of the cmp engine.
> > > >
> > > > If you have any insight into this issue, please speak-up.
> > > >
> > > > -dain
> > > >
> > > >
> > > > _______________________________________________
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