[hibernate-dev] org.hibernate.engine.jdbc.dialect.spi.DialectResolver

[Emmanuel Bernard]

I imagine the DB name + version will be provided by the user somehow.
We could also have Hibernate build a DatabaseMetadata implementation returning the data provided by the user.
That would avoid changing the contract. The main drawback is that DatabaseMetadata has many more methods
we would not be able to honor.

On 29 août 2012, at 19:58, Steve Ebersole wrote:

> Like I said in the original email, the connection may or may not be 
> available.  Which means we cannot rely on it being available.  Nor do 
> we rely on it being available today either btw.  The difference is just 
> that today in those cases we expect the user to manually name the 
> dialect to use.
> 
> On Wed 29 Aug 2012 12:26:17 PM CDT, Max Rydahl Andersen wrote:
>> hmm - any reason why jpa won't pass in DatabaseMetadata ?
>> 
>> how would one identify name and version anyway if that is not available ?
>> 
>> /max
>> 
>> On 29 Aug 2012, at 16:43, Steve Ebersole <steve at hibernate.org> wrote:
>> 
>>> I think we need to consider changing DialectResolver to fit with some
>>> upcoming JPA 2.1 features.
>>> 
>>> JPA 2.1 is adding some form of schema export.  The initial plan there is
>>> to identify the "dialect" to target by passing in the (1) database name
>>> and (2) database version as it would come from JDBC DatabaseMetaData.
>>> The connection may or may not be available.
>>> 
>>> Currently we just pass the DatabaseMetaData to the DialectResolver:
>>> 
>>> public Dialect resolveDialect(DatabaseMetaData metaData)
>>> 
>>> The original thinking was to support resolvers looking at information
>>> other than just name/version ion making the determination (or even in
>>> potentially configuring the Dialect before return).  However all our
>>> implementations are based on just name/version resolution.
>>> 
>>> Even worse the current proposal proposes using (String)
>>> DatabaseMetaData#getDatabaseProductVersion whereas we use (int)
>>> DatabaseMetaData#getDatabaseMajorVersion and (int)
>>> DatabaseMetaData#getDatabaseMinorVersion inside the standard resolver
>>> 
>>> So should we change this contract?
>>> 
>>> public Dialect resolveDialect(String dbName, int majorVersion, int
>>> minorVersion)
>>> 
>>> or
>>> 
>>> public Dialect resolveDialect(String dbName, String dbVersion)
>>> 
>>> WDYT?
>>> 
>>> --
>>> steve at hibernate.org
>>> http://hibernate.org
>>> _______________________________________________
>>> hibernate-dev mailing list
>>> hibernate-dev at lists.jboss.org
>>> https://lists.jboss.org/mailman/listinfo/hibernate-dev
>> 
> 
> --
> steve at hibernate.org
> http://hibernate.org
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