Hi Mario,
As far as I'm aware there is no do***entation around with an equivalent
mapping, at least I've not seen one, but I'm a newbie to the Postgresql
community myself. The postgresql driver is an almost fully compliant
JDBC 3.0 level driver with some JDBC level 4.0 features. So other than
the exclusions, http://jdbc.postgresql.org/todo.html,
and the driver/db
specific extensions,
http://jdbc.postgresql.org/do***entation/83/ext.html,
you can pretty
much derive the mappings, and if you get stuck, you can always jump into
the source code of the driver. Any mapping is two step: from db to
java.sql.Types to java. So you can get the java.sql.Types to java
mapping from lots of online sources such as
http://java.sun.com/j2se/1.4.2/docs/guide/jdbc/getstart/mapping.html#996858,
or http://java.sun.com/javase/6/docs/api/java/sql/Types.html
and the
java.sql.Types to db mappings from the postgresql jdbc driver source
code, http://jdbc.postgresql.org/download.html.
When using the driver directly with jdbc from Java, I haven't
experienced any problems with a wide range of data types. However
Hibernate has been a whole different story. Its postgresql dialect is
somewhat deficient. When attempting to do any reverse engineering,
character types are mapped incorrectly to char[] and accordingly fail,
while character varying gets correctly mapped to String. The new uuid
data type gets mapped to either Serializable, byte[], or in some cases
to b[ of which there is no actual java type, all of which is also
incorrect, but also indicates that there are at least 3 distinct paths
through the Hibernate reverse engineering code to derive three different
java types from the one database type, one of which isn't even a type at
all. So to get JPA/Hibernate working through the postgresql JDBC driver
has taken some level of manual intervention and some database specific
modifications in my code that limit the ****tability of the DAO layer.
Let me know if I have not addressed your question or if you are still
struggling with mapping issues, not that I'll necessarily be able to
assist.
Cheers,
Andy
mario.g.pavlov@[EMAIL PROTECTED]
wrote:
> Hi list,
> I'm sorry for asking this question, I'm sure it's been answered many
times but
> I didn't manage to find the answer anywhere.
> So the question is how do PostgreSQL data types map to Java data types ?
> I've found that MySQL answers this question very good:
>
http://dev.mysql.com/doc/refman/5.0/en/connector-j-reference-type-conversions.html
> I hope there is similar peace of do***entation for PostgreSQL!
>
> thank you
>
> Regards
> MGP
>
>
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