Q 4 C. Bauer & G. King (3): Hibernate = Strict OO

[Gian Franco]

Dear authors,

Does Hibernate 'impose' a strict
object oriented view of the
database? I mean, can't I just
peek into a database table in
the old fashioned way but using
Hibernate?

Cheers,

Gian Franco Casula

[Alexandru Popescu]

Is your question asking about Hibernate allowing to use normal SQL statements?
If yes, than the answer is yes too. Hibernate Session offers the means to execute normal SQL querying.

[Ko Ko Naing]

Originally posted by Gian Franco Casula:
Does Hibernate 'impose' a strict
object oriented view of the
database? I mean, can't I just
peek into a database table in
the old fashioned way but using
Hibernate?

Hi Gian,
If you just peek into a databse table, you can't apply the OO Concept from your peeking... By using Hibernate, you can get advantages of OO from it, which are mapped to the ralational database... For instance, reusability, inheritence and so on...

[somkiat puisungnoen]

Originally posted by Ali Pope:
Is your question asking about Hibernate allowing to use normal SQL statements?
If yes, than the answer is yes too. Hibernate Session offers the means to execute normal SQL querying.

In hibernate use MUST USE "Hibernate Query Language[HQL]"

Hibernate Query Language[HQL] designed as a "minimal" object-oriented extension to SQL, provides an elegant bridge between the object and relational worlds"

[Gian Franco]

Hi Somkiat,

My understanding is that you can use HQL, but
can use vendor SQL as well.

I guess this is done in order to allow programmers
to use a vendor's SQL peculiarities if necessary.

Cheers,

Gian Franco Casula

[Christian Bauer]

I answered this question here: http://www.coderanch.com/t/214937/ORM/java/Bauer-King-Hibernate-formulating-queries

[Gavin King]

I like to say that Hibernate unifies relational querying with object modelling.

So no, it is not "strict" OO in the sense that it has no concepts from outside the OO mindset. Hopefully, Hibernate helps you think about your data in both ways, by easing the conceptual gap between the two models.

[Pradeep bhatt]

Could I use hibernate to persist data in non -relational datastore like OODBMS or flat file? :roll:

[Gavin King]

Nope, definitely not!

(Why would you want to?)

[somkiat puisungnoen]

Originally posted by Pradeep Bhat:
Could I use hibernate to persist data in non -relational datastore like OODBMS or flat file? :roll:

Hibernate Support Database

Hibernate requires JDK 1.2 or later (some people have run successfully under 1.1.8) and has been tested with the following SQL databases:

DB2 7.1, 7.2, 8.1
MySQL 3.23, 4.0
PostgreSQL 7.1.2, 7.2, 7.3, 7.4
Oracle 8i, 9i
Sybase 12.5 (JConnect 5.5)
Daffodil DBv3.1
Interbase 6.0.1 (Open Source) with Firebird InterClient 2.01
HypersonicSQL 1.61, 1.7.0
Microsoft SQL Server 2000
Mckoi SQL 0.93
Data Replication Tool
Progress 9
Pointbase Embedded 4.3
SAP DB 7.3

Hibernate is also thought to be compatible with the latest versions of:

Informix
Ingres
FrontBase
Firebird (1.5 with JayBird 1.01)

[Pradeep bhatt]

Originally posted by Gavin King:
Nope, definitely not!

(Why would you want to?)

For e.g. my application reads/updates data from two datastores. First one is RDBMS and 2nd one is some legacy system. I was thinking if Hibernate could be used in both cases? :roll:
Thanks Gavin.

[Gavin King]

No, we can't talk to legacy data, unless there is a SQL layer over the top (which is the case, in some cases).

[somkiat puisungnoen]

Originally posted by Pradeep Bhat:


For e.g. my application reads/updates data from two datastores. First one is RDBMS and 2nd one is some legacy system. I was thinking if Hibernate could be used in both cases? :roll:
Thanks Gavin.

No, you can not do it.

BUT you can use DAO or EIS system to solve this problem.