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From Patrick Linskey <plins...@gmail.com>
Subject Re: SchemaGenerator vs. SchemaFactory
Date Mon, 01 Feb 2010 23:56:42 GMT
Hi,

A SchemaFactory is an interface used by a bunch of JDBC-ish code to  
read and modify the current schema, and is pretty bare-bones.

A SchemaGenerator is a class used by the schema creation /  
introspection process to convert DB-specific metadata to Schema  
objects etc.

> Suppose I'm writing a database/OpenJPA-related tool.  If I were  
> looking for
> general-purpose connect-to-a-database-and-barf-out-a-SchemaGroup
> functionality, would I be better off asking someone to supply an  
> instance of
> a SchemaGenerator, or an arbitrary SchemaFactory, if I were simply  
> going to
> do the bare minimum in terms of calling methods?

Probably a SchemaFactory. But it's a pretty thin interface.

-Patrick

On Feb 1, 2010, at 3:37 PM, Laird Nelson wrote:

> Can someone outline for me what the difference is between these two  
> classes
> (other than that SchemaGroup is a class and SchemaFactory is an  
> interface)?
>
> To my eyes they are responsible for the same job.
>
> It also seems like a SchemaGenerator should, in all cases, be a
> SchemaFactory.
>
> Suppose I'm writing a database/OpenJPA-related tool.  If I were  
> looking for
> general-purpose connect-to-a-database-and-barf-out-a-SchemaGroup
> functionality, would I be better off asking someone to supply an  
> instance of
> a SchemaGenerator, or an arbitrary SchemaFactory, if I were simply  
> going to
> do the bare minimum in terms of calling methods?
>
> Thanks for any pointers.  I know this is a vague question, but I'm  
> looking
> for vague answers.  :-)  What I mean is, I'm mainly interested in  
> reasons
> that these two classes look so similar--perhaps the mighty Abe White  
> forgot
> what he had already written?  Or had other ideas in mind?
>
> Best,
> Laird

-- 
Patrick Linskey
202 669 5907


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