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From Rainer Döbele <doeb...@esteam.de>
Subject re: Spring example
Date Wed, 17 Feb 2010 21:44:31 GMT
Hi Eike,

finally I had the chance to look at your spring example and I think it is pretty cool.
Thank you very much for providing this example - great work!
I am sure it will be a good guide for many users who wish to use Empire-db with Spring.

In order to simplify it a bit I have removed the dependency to the basic example project and
copied the database definition and sample bean over. 
I think this example is ready for distribution with our upcoming release.

Regards
Rainer


Eike Kettner wrote:
> Re: how to add a "foreign" table
> 
> Hi Rainer
> 
> thank you for your quick response; and you're very welcome with this
> spring example, I'm glad if can help.
> 
> My final goal was to create some kind of migration script to upgrade my
> db schema, because my app will contain some new features in next
> versions which will add tables and columns to the existing db schema. I
> want to compare two instances of DBDatabase and generate the sql ddl
> statements. So actually, I don't really need to add the table to the
> other db, but I want to create arbitary sql ddl statements (for
> DBTable,
> DBColumn, DBView...) using a different driver. This works with
> DBDatabse
> already, I can specify a DBDatabaseDriver there and the method will
> change the driver temporarily. Therefor I tried to either add the
> missing table from the one db to the other or to set the
> DBDatabaseDriver of the first db into the second, so I can use the
> second DB to create its table - but now with the driver from the first
> db...
> 
> I somehow got an evil workaround by serializing the two DBDatabses and
> while deserializing back, I inject my desired driver into the
> DBDatabases. So I end up with a clone of the db having my target driver
> attached.
> 
> Thank you four your help!
> Eike
> 
> Rainer Döbele wrote:
> > Hi Eike,
> >
> > first I want to thank you very much for your submission of the spring
> example.
> > Unfortunately I did not have the chance to look at it so far - but I
> am quite keen to do so.
> > I'll let you know when I have.
> >
> > Now about your question:
> > A DBTable object may only belong to one database object just like an
> XMLElement belongs to its XMLDocument.
> > This assignment is usually performed on creation of the DBTable and
> there is no mechanism to change it.
> >
> > Hence if you really need to need a copy of the table object of one
> database in another one you need to create a new instance of the table
> object.
> > Normally you would just create a instalce of the table like this:
> >
> >     DBTable t = new DB1.SomeTable(db2);
> >
> > If your code should be more generic then you might use something
> like:
> >
> >     DBTable t = db1.getTable(...);
> >     t.getClass().getConstructor(DBDatabase.class).newInstance(new
> Object[] { db2 });
> >
> > This assumes that the table has a constructor that takes the db as a
> parameter.
> >
> > Hope this is what you need.
> > Otherwiese I would need to know what excatly you are trying to
> achieve with this.
> >
> > Regards
> > Rainer
> >
> >
> > Eike Kettner wrote:
> >
> >> re: how to add a "foreign" table
> >>
> >> Hello all,
> >>
> >> I'm facing a problem that I want to add a table from one db to
> another
> >> db. I have two DBDatabases and I like to add a table from DB1 to
> DB2,
> >> something like this:
> >>
> >>
> >>   DBDatabase db1 = ..
> >>   DBDatabase db2 = ..
> >>
> >>   DBTable table1 = db1.getTable(0);
> >>
> >>   db2.addTable(table1);
> >>
> >>
> >> actually, what i want is to create a table on DB2 that is present on
> >> DB1, without too much coding ;-)
> >>
> >> Thankful for any help!
> >>
> >> Kind regards,
> >> Eike
> >>
> >
> >


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