load object without primary key and HQL

sunilkumarsh · **Posted:** Tue May 03, 2005 12:15 pm

I am using hibernate 3 version.

I want to load the object without passing the ID.
I dont want to use HQL.

What I want is .....suppose i have class employee with few records in it.
and I want all the records from this class

now the question can this be done without using HQL.

If yes how ?

Secondly I also want to know If I am loading the class can I load it without passing the primary key.
Can I load it by passing some other attribute of class.
Pls suggest I am in deep trouble .....

:(

Thanks in advance

pksiv · **Posted:** Tue May 03, 2005 12:57 pm

sunilkumarsh wrote:

I am using hibernate 3 version.

I want to load the object without passing the ID.
I dont want to use HQL.

What I want is .....suppose i have class employee with few records in it.
and I want all the records from this class

now the question can this be done without using HQL.

If yes how ?

Secondly I also want to know If I am loading the class can I load it without passing the primary key.
Can I load it by passing some other attribute of class.
Pls suggest I am in deep trouble .....

:(

Thanks in advance

You can return all Employee objects using session.createCriteria(Employee.class).list();

You can only execute the session.load() method using the PK but there are many other ways to get your data loaded, including using Criteria and Query objects. Both allow you to specifiy properties other than the primary key.

Check out the docs... there are many examples.

sunilkumarsh · **Posted:** Wed May 04, 2005 6:32 am

Thanks a lot for answering my earlier question.
I tried it and its working.....

It will be nice of u ...
if u could make one more thing clear to me ....

Is it oky to use HQL?
If yes which situation should we use it ?

or we should always try and fetch objects using traversing ?

which of the 2 ways is efficient ?
whats the advantage of using either of them ?

pksiv · **Posted:** Wed May 04, 2005 9:28 am

sunilkumarsh wrote:

Thanks a lot for answering my earlier question.
I tried it and its working.....

It will be nice of u ...
if u could make one more thing clear to me ....

Is it oky to use HQL?
If yes which situation should we use it ?

or we should always try and fetch objects using traversing ?

which of the 2 ways is efficient ?
whats the advantage of using either of them ?

In a majority of cases, you shouldn't need to use HQL but there are definitely cases where it comes in handy.

Check out section 14 Tips and Tricks of the documentation. I use HQL to check if a certain data exists in the database without having to return the data

Code:

select count(*) from Employee emp where emp.lastName = :lastName and emp.firstName = :firstName

Also anytime I need to use a subselect for example:

Code:

from MyObject myo where myo.dateCollected = 
          (select max(myo2.dateCollected)
             from MyObject myo2 where myo2.id = myo.id) 

pksiv · **Posted:** Wed May 04, 2005 9:29 am

I should note that I haven't worked with all of the new features that Hibernate 3 has added so there may be even fewer reasons to use HQL, but I wouldn't be afraid to use it. It's in the product for a reason.

geoharp · **Posted:** Wed May 04, 2005 3:53 pm

The reason why I am attempting to use HQL is that our compnies product runs against Oracle or mssql server.

The language is basically sql but there are some differences.
I am hoping to use HQL to resolve the differences so that I dont have to write
2 different sets of querys.

Just a thought