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.
>
>
Exactly
> 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.
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