Re: Am I overseen ?

On 18 Okt., 18:22, scott(dot)marl(dot)(dot)(dot)(at)gmail(dot)com ("Scott Marlowe") wrote:
> On 10/18/07, Lothar Behrens <lothar(dot)behr(dot)(dot)(dot)(at)lollisoft(dot)de> wrote:
>
>
>
> > On 18 Okt., 17:17, br(dot)(dot)(dot)(at)zijn-digital(dot)com (brian) wrote:
> > > Lothar Behrens wrote:
> > > > Hi,
>
> > > > Several groups I post most of them does not answer.
> > > > Did noone see my postings ?
>
> > > > Please at least give me one answer :-)
>
> > > > Thanks, Lothar
>
> > > ping
>
> > > What was your query?
>
> > I do convert an UML XMI model to a database script to create the
> > database schema.
> > To enable multiple iterations I need conditional alter table add
> > column like syntax.
>
> > For sample:
>
> > if not exsist column a in table b then
> > alter table b add a char(100);
>
> > Is there any way to do this ?
>
> What kind of tools are you familiar with? I'm guessing you could
> write something in perl or php to do it. Or do you want to do it in
> sql? I'm sure you could do it in plpgsql or some other pl/language,
> if you want it all in the db.

Just a copy of my mail.

UML is only a hint, where my source is. I transform it to a big SQL
query
to be executed inside a C/C++ application. So no scripting available
yet.

Also no XML decoding to issue ODBC API commands to determine existing
tables / columns.

> But I'm not that familiar with UML as to say what's the best approach.

Transforming it to SQL queries is best for me, because the application
model
is stored in SQL database. UML is only a possible input to better
model the app.

ER diagramming tools that support XML export would also be an option.

> Normally when you get thundering silence, you've asked a question no
> one feels real qualified to answer, and rather than answer it halfway,
> they just leave it for the next guy to get.

In my opinion the question was clear. How to alter table if the column
not already
inserted of later of given type.

I know about the systables of postgresql as each other database system
has - propably :-)
But I'm not that familar with it.

I need a sample how that is done in plain SQL (i pass the script via
ODBC to the database).

Lothar