db-torque-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Ivano Luberti <lube...@archicoop.it>
Subject Re: newbie and generator rewriting
Date Fri, 12 Feb 2010 09:35:20 GMT
Ok, Gregg I will read your links...of course I will need some time
Some comments in line

Greg Monroe ha scritto:
> I agree TF here. It's hard and will always be wrong for someone or some
> version of SQL.  Remember Torque has to work across all major DB server. 
> But, as TF said, it's a good tool to get a basic snapshot that can be modified 
> to match. IMHO, It's part of the nice rapid application development point of 
> view that Torque has.
> FWIW, if you dig into how you would do this, you find that you're dependent 
> on what the JDBC driver returns about the database. If I remember the JDBC 
> specs, the meta data you have to depend on has a lot of "holes" in it as far 
> as finding the underlying DB structure.  Plus, there is a lot of variation 
> in how different drivers implement it.
As I wrote answering to TF, using Postgres I didn't find any hole but
maybe I was not using features to expose them.

> I think it's important to consider a couple of cases for SQL updates.  The
> first is the major structural changes that requires a lot of testing, etc. 
> as TF talks about above.
> The second is case is the additive / minor updates one.  E.g. I've added more 
> tables to  support more features and maybe a few columns to existing tables.  
> This is a much more straight forward change and sql-xml is very useful in this.

> FWIW, in the latter case, I tend to do is create the SQL build from the 
> *schema.xml that has been checked in.  Create a new DB with tables from it.  
> Do an sql->xml process on the development/test DB and on the new DB.  Compare 
> the two and resolve any "whoops... I added that column to the DB but not the 
> XML. Repeat until they match... (plus keep and eye out for missing FK/Indices).
> Then I'll use this XML with the DDLUtils API to create the basic ALTER script.
> It has the ability to do an compare of the real DB to an XML and create a
> nice SQL script.  This isn't perfect, but it's a good start and with some 
> review and quick editing, give me the script to run during the code upgrade.
Ah ok: that is a good suggestion. I didn't know about DDL utils api
until TF pointed them to me

> Hope this isn't too confusing since I've been typing on it piece meal over
> the day.
I think it is quite clear.
Now I have to make room in my schedule to find time to read your material.
I hope to do next week , but I have two deliveries.


dott. Ivano Mario Luberti
Archimede Informatica societa' cooperativa a r. l.
Sede Operativa
Via Gereschi 36 - 56126- Pisa
tel.: +39-050- 580959
tel/fax: +39-050-9711344
web: www.archicoop.it

To unsubscribe, e-mail: torque-dev-unsubscribe@db.apache.org
For additional commands, e-mail: torque-dev-help@db.apache.org

View raw message