I wasn't trying to push an ORM view on your approach, with which I quite
agree :-)
Also, in this contexts, I'm not interested in traditional JavaBeans.
My only concern is that empire-db's API for querying seems a bit
disconnected from the API for writing, and that operations that are
simple for a single record become significantly (and in my opinion
unnecessarily) difficult for record sets.
I'm really on your side with your analysis of ORM defects, so I'm saying
this in the most constructive sense.
Regards
Paolo
Rainer Döbele wrote:
Hi Paolo,
even though what you want is possible with Empire-db, it is not the recommended
approach.
Your desire to obtain a List<DBRecord> is more the way traditional OR-Mappers
work and that I criticize: They usually force you to work with data bean objects that
match a record of the database table (full entity beans) even though it is in most
cases (as with almost every list) neither necessary nor required. Especially when you
have user interaction then a list you present to the user rarely shows a single table
with all its columns.
For a better understanding I recommend reading the following article
http://incubator.apache.org/empire-db/empiredb/hibernate.htm
especially the section "Dynamic queries: The select dilemma"
So what I recommend is the following:
1. Use DBCommand and DBReader to obtain and present a list to the user. Select
the primary key and only columns that you want to display to the user. You may
use reader.getBeanList() to obtain a list of traditional Java Beans for your
list display needs.
2. If the user selects a in individual record, read it user DBReader.read().
The entire record then will be fetched from the database and you may change and
update it. Then the user may select and change another record.
Alternatively if multiple records are to be changed on one click of a button,
then do the following:
- Perform a new query for all records that need to be changed and iterate
though them using a DBReader.
- Initialize a DBRecord object for the current row using initRecord()
- With the DBRecord change the value and call update().
- Continue with the next record.
Regards
Rainer
